Essential college physics serway, vuille 1st edition

Essentials of College Physics provides students with a clear and logicalpresentation of the basic concepts and principles of physics.. Essentials of College Physics provides a wealth of

PEDAGOGICAL USE OF COLOR

CapacitorsInductors (coils)

Lightbulbs

AC sources

Batteries and other

Torque (t) and

angular momentum

(L) vectors

Acceleration vectors (a)

Acceleration component vectors

Australia · Brazil · Canada · Mexico · Singapore · Spain · United Kingdom · United States

Vice President, Editor-in-Chief, Sciences: Michelle Julet

Development Editor: Ed Dodd

Editorial Assistant: Jessica Jacobs

Technology Project Manager: Sam Subity

Marketing Manager: Mark Santee

Marketing Assistant: Michele Colella

Marketing Communications Manager: Bryan Vann

Project Manager, Editorial Production: Teri Hyde

Creative Director: Rob Hugel

Art Director: Lee Friedman

Production Service: Joan Keyes, Dovetail Publishing Services, Inc Text Designer: Patrick Devine

Photo Researcher: Jane Sanders Miller Copy Editor: Kathleen Lafferty Illustrator: Rollin Graphics, Progressive Information Technologies Cover Designer: Patrick Devine

Cover Image: Adrian Weinbrecht/Photolibrary Cover Printer: Quebecor World/Dubuque Compositor: G&S Typesetters, Inc.

Printer: Quebecor World/Dubuque

ExamView ® and ExamView Pro ® are registered trademarks of FSCreations, Inc Windows is a registered trademark of the Microsoft Corporation used herein under license Macintosh and Power Macintosh are registered trademarks of Apple Computer, Inc Used herein under license.

© 2007 Thomson Learning, Inc All Rights Reserved Thomson Learning WebTutor™ is a trademark of Thomson Learning, Inc.

Thomson Higher Education

10 Davis Drive Belmont, CA 94002-3098 USA

Library of Congress Control Number: 2005932024

ISBN 0-495-10619-4

© 2007 by Raymond A Serway.

ALL RIGHTS RESERVED No part of this work covered by the

copy-right hereon may be reproduced or used in any form or by any

means — graphic, electronic, or mechanical, including photocopying,

recording, taping, web distribution, information storage and retrieval

systems, or in any other manner — without the written permission

of the publisher.

Printed in the United States of America

1 2 3 4 5 6 7 10 0 9 0 8 0 7 0 6

For more information about our products, contact us at:

Thomson Learning Academic Resource Center

1-800-423-0563

For permission to use material from this text or product, submit a

request online at http://www.thomsonrights.com.

Any additional questions about permissions can be submitted by

e-mail to thomsonrights@thomson.com.

The Foundation for Success

Building the right course for you and your students is easy when

Because every course is as unique as its instructor—and its students—you need an approach

tai-lored to your distinct needs No matter how you decide to execute your course, Essentials of College

Physics, provides the proven foundation for success This accessible and focused text includes

a broad range of engaging and contemporary applications that motivate student understanding of how

physics works in the real world And with its extraordinary range of powerful teaching and learning

resources, it’s easy for you to craft a course that fits your exact requirement with:

the book, including hints and feedback for students

 Access to the PhysicsNow ™ student tutorial system—interactive, integrated

learning technology that puts concepts in motion

 Premium book-specific content for audience response systems that lets

you interact with your students directly from your own PowerPoint®lectures

 A multimedia presentation tool that lets you incorporate colorful images and

clarifying animations into every lecture

We know that providing your students with a solid foundation in

the basics is the key to student success and that means

providing them with proven, time-tested content As you

peruse the following pages of this PREVIEW, be sure to

note the adjacent diagram indicating the different

com-ponents of our integrated, interrelated program No

matter what kind of course you want to deliver—

whether you offer a more traditional

text-based course, you’re interested in using

or are currently using an online homework

management system, or you are ready

to turn your lecture into an interactive

learning environment through an

audi-ence response system—you

can be confident that proven

con-tent provides the foundation for

each and every component

Whatever your goals are for you and your students, Essentials of College Physics

features the content and the courseware to get you there— without the risk.

Essentials of College Physics provides students with a clear and logical

presentation of the basic concepts and principles of physics With the text asthe foundation, coupled with extraordinary media integration, it’s easy to build

a course that gives every student the maximum opportunity for success

iv

Briefer than the average college physics text,

Essentials of College Physics

compre-hensively covers all the standard topics in

classical and modern physics Instructors

will notice a clean and clear dialogue with

the student, the book’s uncluttered look and

feel, and attention paid to language The

154 Chapter 7 Rotational Motion and the Law of Gravity

7.4 CENTRIPETAL ACCELERATION

Figure 7.5a shows a car moving in a circular path with constant linear speed v Even

though the car moves at a constant speed, it still has an acceleration To

under-stand this, consider the defining equation for average acceleration:

[7.12]

The numerator represents the difference between the velocity vectors and

These vectors may have the same magnitude, corresponding to the same speed, but

the car’s velocity as it moves in the circular path is continually changing, as shown always points toward the center of the circle Such an acceleration is called a

centripetal (center-seeking) acceleration Its magnitude is given by

[7.13]

To derive Equation 7.13, consider Figure 7.6a An object is first at point 훽 with velocity at time t iand then at point 훾 with velocity at a later time t f We assume that and differ only in direction; their magnitudes are the same

(v i  v f  v) To calculate the acceleration, we begin with Equation 7.12,

[7.14]

where is the change in velocity When t is very small, s and u are also very small In Figure 7.6b, is almost parallel to , and the vector is ap- proximately perpendicular to them, pointing toward the center of the circle In the limiting case when t becomes vanishingly small, points exactly toward the center of the circle, and the average acceleration becomes the instantaneous acceleration From Equation 7.14, and point in the same direction (in this limit), so the instantaneous acceleration points to the center of the circle.

The triangle in Figure 7.6a, which has sides s and r, is similar to the one formed by the vectors in Figure 7.6b, so the ratios of their sides are equal:

r r O

i f

(b)

훽 훾

v

v v

Figure 7.5(a) Circular motion of

a car moving with constant speed

(b) As the car moves along the lar path from 훽 to 훾, the direction

circu-of its velocity vector changes, so the car undergoes a centripetal acceleration.

v

v v

Figure 7.6 (a) As the particle moves from 훽 to 훾, the direction of its velocity vector changes from to (b) The construction for deter- mining the direction of the change in velocity , which is toward the center of the circle.v:

The International System of units (SI)

is used throughout the book The U.S.

customary system of units is used only

to a limited extent in the problem sets of the early chapters on mechanics.

Vectors are denoted in face with arrows over them.

bold-This makes them easier

to recognize.

starts with the foundation

Essentials of College Physics provides a wealth of outstanding

examples and problem sets to help students develop critical

prob-lem-solving skills and conceptual understanding

 All worked Examples include six parts:

Goal, Problem, Strategy, Solution, Remarks,

and Exercise/Answer The “Solution” portion of

every Example is presented in two-columns to

enhance student learning and to help reinforce

physics concepts In addition, the authors have

taken special care to present a graduated level

of difficulty within the Examples so students are

better prepared to work the end-of-chapter

Problems.

8.4 Examples of Objects in Equilibrium 181

EXAMPLE 8.4 Locating Your Lab Partner’s Center of Gravity

Goal Use torque to find a center of gravity.

Problem In this example, we show how to find the tion of a person’s center of gravity Suppose your lab part-

loca-715 N (160 lb) You can determine the position of his board supported at one end by a scale, as shown in

Figure 8.9 If the board’s weight w b is 49 N and the scale

reading F is 3.50 10 2 N, find the distance of your lab ner’s center of gravity from the left end of the board.

part-Strategy To find the position xcgof the center of gravity, compute the torques using an axis through O Set the sum of the torques equal to zero and solve for xcg

L L/2

b

xcg

O

F n

w w Figure 8.9 (Example 8.4) Determining your lab partner’s center of gravity.

Solution

Apply the second condition of equilibrium There is no torque due to the normal force because its moment arm is zero.

xcg FL  w b (L/2)

w

Remarks The given information is sufficient only to determine the x -coordinate of the center of gravity The other

two coordinates can be estimated, based on the body’s symmetry.

Exercise 8.4

Suppose a 416-kg alligator of length 3.5 m is stretched out on a board of the same length weighing 65 N If the board

of gravity.

Answer 1.59 m

8.4 EXAMPLES OF OBJECTS IN EQUILIBRIUM

Recall from Chapter 4 that when an object is treated as a geometric point, shown that for extended objects a second condition for equilibrium must also be dure is recommended for solving problems that involve objects in equilibrium.

equilib-Problem-Solving Strategy Objects in Equilibrium

1 Diagram the system Include coordinates and choose a convenient rotation axis

for computing the net torque on the object.

2 Draw a free-body diagram of the object of interest, showing all external forces

act-ing on it For systems with more than one object, draw a separate diagram for each

object (Most problems will have a single object of interest.)

 New! Just-In-Time Math Tutorials!

An emphasis on quantitative problem-solving is provided in the

Math Focus boxes These boxes develop mathematical methods

important to a particular area of physics, or point out a technique

that is often overlooked Each Math Focus box has been placed

within the applicable section of the text, giving students just-in-time

support A complete Appendix provides students with additional

math help applied to specific physics concepts.

Math Focus 6.1 One-Dimensional Elastic Collisions

The usual notation and subscripts used in the

equa-tions of one-dimensional collisions often obscure the

underlying simplicity of the mathematics In an elastic

collision, the rather formidable-looking Equations 6.10

and 6.11 are used, corresponding to conservation of

momentum and conservation of energy, respectively.

In a typical problem, the masses and the initial

veloci-ties are all given, leaving two unknowns, the final

ve-locities of the colliding objects Substituting the more

common-looking variables, X  v 1f and Y  v 2 f,

to-gether with the known quantities yields equations for

a straight line (the momentum equation) and an

el-lipse (the energy equation) The mathematical

solu-tion then reduces to finding the intersecsolu-tion of a

straight line and an ellipse.

Example:In a one-dimensional collision, suppose the

first object has mass m1  1kg and initial velocity

v 1i 3m/s, whereas the second object has mass

m2 2kg and initial velocity v 2i 3m/s Find the

final velocities for the two objects (For clarity,

signifi-cant figure conventions are not observed here.)

Solution:Substitute the given values and X  v1fand

Y  v 2 finto Equations 6.10 and 6.11, respectively, and

simplify, obtaining

3  X  2Y (1)

27 X2 2Y2 (2) Equation (1) is that of a straight line, whereas Equation

(2) describes an ellipse Solve Equation (1) for X

and substitute into Equation (2), obtaining 27

(3  2Y) 2 2Y2 , which can be simplified to

Y2 2Y  3  0

In general, the quadratic formula must now be

ap-plied, but this equation factors, giving Y  v 2 f

1 m/s or 3m/s Only the first answer, 1m/s, makes sense Substituting it into Equation (1) yields

X  v 1f 5m/s

It is also possible to use Equation 6.10 together with the derived Equation 6.14 This situation, illustrated tion of two straight lines It’s easier to remember the equation for the conservation of energy than the spe- cial Equation 6.14, so it’s a good idea to be able to solve such problems both ways.

Essentials of College Physics includes time-tested as well as new

peda-gogy that adheres to the findings of physics education research to helpstudents improve their conceptual understanding

and conceptual understanding

 A wealth of interesting and relevant

Applications reveals the role physics plays

in our lives and in other disciplines These

Applications are woven throughout the text

narrative and are indicated with a margin note For biology and pre-med students, icons point the way to various practical and interesting

Applications of physical principles to biology

and medicine With this edition the authors

have increased the number of life

science-oriented applications and end-of-chapter

Problems to help motivate students to master

the content.

288 Chapter 11 Energy in Thermal Processes

The same process occurs when a radiator raises the temperature of a room.

The hot radiator warms the air in the lower regions of the room The warm air air from above sinks, setting up the continuous air current pattern shown in Figure 11.9.

An automobile engine is maintained at a safe operating temperature by a combination of conduction and forced convection Water (actually, a mixture of the engine block increases in temperature, energy passes from the hot metal to the engine and into the radiator, carrying energy along with it (by forced convection).

the cooler outside air, and energy passes into the air by conduction The cooled process of air being pulled past the radiator by the fan is also forced convection.

wa-The algal blooms often seen in temperate lakes and ponds during the spring or fall are caused by convection currents in the water To understand this process, gradients, with an upper, warm layer of water separated from a lower, cold layer by the water break down this thermocline, setting up convection currents that surface The nutrient-rich water forming at the surface can cause a rapid, tempo- rary increase in the algae population.

Photograph of a teakettle, showing

steam and turbulent convection air

(a) Summer layering of water

Figure 11.10 (a) During the summer, a warm upper layer of water is separated from a cooler lower layer by a thermocline (b) Convection currents during the spring or fall mix the water and can cause algal blooms.

Figure 11.9 Convection currents

are set up in a room warmed by a

radiator.

9.3 Density and Pressure 211

The pressure at a specific point in a fluid can be measured with the device tured in Figure 9.7b: an evacuated cylinder enclosing a light piston connected to a merged in a fluid, the fluid presses down on the top of the piston and compresses

pic-force exerted by the spring Let F be the magnitude of the pic-force on the piston and

the spring is spread out over the entire area, motivating our formal definition of pressure:

If F is the magnitude of a force exerted perpendicular to a given surface of area A, then the pressure P is the force divided by the area:

[9.7]

SI unit: pascal (Pa)

Because pressure is defined as force per unit area, it has units of pascals (newtons squared Atmospheric pressure at sea level is 14.7 lb/in 2 , which in SI units is 1.01 10 5 Pa.

As we see from Equation 9.7, the effect of a given force depends critically on the area to which it’s applied A 700-N man can stand on a vinyl-covered floor in metal cleats protruding from the soles can do considerable damage to the floor.

ing the pressure in those areas, resulting in a greater likelihood of exceeding the ultimate strength of the floor material.

Snowshoes use the same principle (Fig 9.8) The snow exerts an upward mal force on the shoes to support the person’s weight According to Newton’s shoes on the snow If the person is wearing snowshoes, that force is distributed relatively low and the person doesn’t penetrate very deeply into the snow.

nor-P
F

A

TIP 9.1 Force and Pressure

Equation 9.7 makes a clear tion between force and pressure Another important distinction is that

distinc-force is a vector and pressure is a scalar.

There is no direction associated with pressure, but the direction of the force associated with the pressure is perpendicular to the surface of interest.

Pressure

Figure 9.8Snowshoes prevent the person from sinking into the soft snow because the force on the snow is spread over a larger area, reducing the pressure on the snow’s surface

After an exciting but exhausting lecture, a physics fessor stretches out for a nap on a bed of nails, as in Figure 9.9, suffering no injury and only moderate dis- comfort How is this possible?

pro-Explanation If you try to support your entire weight

on a single nail, the pressure on your body is your weight divided by the very small area of the end of the nail The resulting pressure is large enough to pene- trate the skin If you distribute your weight over several hundred nails, however, as demonstrated by the professor, the pressure is considerably reduced because the area that supports your weight is the total area of all nails in contact with your body (Why is lying on a bed of nails more comfortable than sitting

on the same bed? Extend the logic to show that it

would be more uncomfortable yet to stand on a bed

of nails without shoes.)

Applying Physics 9.1 Bed of Nails Trick

Figure 9.9 (Applying Physics 9.1) Does anyone have a pillow?

 Applying Physics sections allow

stu-dents to review concepts presented in a

section Some Applying Physics examples

demonstrate the connection between the

concepts presented in that chapter and

other scientific disciplines

Tip notations address common student

misconceptions and situations in which

stu-dents often follow unproductive paths.

Approximately 100 Tip sections are found in the

margins, providing students with the help they need to avoid common mistakes

and misunderstandings.

 Quick Quiz questions throughout

the book provide students ample

opportunity to assess their conceptual

understanding

 Checkpoints ask simple questions

based on the text to further reinforce

key ideas.

An MCAT Test Preparation Guide is contained in the preface to help students prepare for the exam

and reach their career goals The Guide outlines key test concepts and directed review activities from

the text and the PhysicsNow student tutorial program to help students get up to speed.

Several components from the text are enhanced in the PhysicsNow

student tutorial program to reinforce material, including the dynamic

Active Figures, which are animated diagrams from the text Labeled

with the PhysicsNow icon, these figures come to life and allow

stu-dents to visualize phenomena and processes that can’t be sented on the printed page.

repre- Also in the PhysicsNow student tutorial

pro-gram are Coached Problems These engaging

problems reinforce the lessons in the text by

taking the same step-by-step approach to

problem solving as found in the text Each

Coached Problem gives students the option

of breaking down a problem from the text into

steps with feedback to ‘coach’ them toward

the solution There are approximately three

Coached Problems per chapter Once the

stu-dent has worked through the problem, he or

she can click

“Try Another” to change the variables in the

problem for more practice.

INTERACTIVE EXAMPLE 4.7 Atwood’s Machine

Goal Use the second law to solve a two-body problem.

Problem Two objects of mass m1and m2, with m2 1 ,

are connected by a light, inextensible cord and hung

cord and pulley have negligible mass Find the

magni-the cord.

Strategy The heavier mass, m2 , accelerates downwards,

in the negative y-direction Since the cord can’t be

in magnitude, but opposite in direction, so that a1 is

posi-tive and a2is negative, and a2 a1 Each mass is acted

on by a force of tension in the upwards direction and a

force of gravity in the downwards direction Active

Fig-Newton’s second law for each mass, together with the

three equations for the three unknowns — a1, a2, and T.

con-(b) Free-body diagrams for the objects.

Log into to PhysicsNow at http://physics.brookscole.com/ecp and go

to Active Figure 4.15 to adjust the masses of objects on Atwood’s chine and observe the resulting motion.

ma-Solution

Apply the second law to each of the two masses

individually:

m1a1 T  m1g (1) m2a2 T  m2g (2)

Substitute a2 a1 into the second equation, and

multiply both sides by 1: m2a1 T  m2g

Add the stacked equations, and solve for a1 : (m1 m2)a1 m2g  m1g (3)

a1 m2 m1

m1 m2g

Substitute this result into Equation (1) to find T : T 2m1m2

m1 m2g

Remarks The acceleration of the second block is the same as that of the first, but negative When m2 gets very large

compared with m1, the acceleration of the system approaches g, as expected, because m2 is falling nearly freely under

the influence of gravity Indeed, m2is only slightly restrained by the much lighter m1 The acceleration of the system

can also be found by the system approach, as illustrated in Example 4.10.

g

m1

 Over 40 of the text’s worked Examples are fied as Interactive Examples and labeled with the

identi-PhysicsNow icon As part of the identi-PhysicsNow

web-based tutorial system, students can engage in an active extension of the problem solved in the correspon-

inter-ding worked Example from the text This often includes

elements of both visualization and calculation, and may also involve prediction and intuition building Students are guided through the steps needed to solve a problem type and are then asked to apply what they have learned

to different scenarios.

reliability of WebAssign make the perfect homework management solution

Whether you are an experienced veteran or a beginner, Enhanced WebAssign

is the perfect solution to fit your teaching goals and student learning needs

Enhanced, easy to use, easy to learn!

http://www.webassign.net

WebAssign is the most utilized, most user-friendly homework management system in physics Designed by physicists for physicists, this system is a trusted teaching companion An enhanced version of WebAssign is

available for Essentials of College Physics, including Active Figures with conceptual questions, end-of-chapter

problems, conceptual questions, quick quizzes, and Active Examples with hints and feedback to guide students

to content mastery Contact your Thomson Brooks/Cole representative for more information

 WebAssign’s simple, user-friendly interface

lets you quickly master the essential functions

like building a class and creating assignments

without a lot of guesswork.

 A powerful GradeBook allows you to manage

your class grades, set grade curves, extend

dead-lines, and export results to an offline

spreadsheet-compatible format

Web Assign

 Active Figures

help students increase visualization skills

Active Figures, which are

animated figures from the text, come to life and

allow students to visualize phenomena and processes that can’t be represented

on the printed page These figures allow students to greatly increase their con- ceptual understanding In addition to viewing animations of the fig-

ures from the text, students can change variables to see the

effects, conduct suggested explorations of the principles involved

in the figure, and take and receive feedback on quizzes related to

the figure In Enhanced WebAssign, you can assign these

simu-lations as a complete homework problem or allow students to

access applicable Active Figures as interactive hints.

Energy can be transferred to a system by heat and by work done on the system In

in understanding engines All such systems of gas will be assumed to be in pressure If that were not the case, the ideal gas law wouldn’t apply and most of the ted with a movable piston (Active Fig 12.1a) and in equilibrium The gas occupies The gas is compressed slowly enough so the system remains essentially in thermo-

thermo-force F through a distance y, the work done on the gas is

where we have set the magnitude F of the external force equal to PA, possible because

the pressure is the same everywhere in the system (by the assumption of equilibrium).

Note that if the piston is pushed downward, y  yf  y iis negative, so we need an

ex-plicit negative sign in the expression for W to make the work positive The change in

volume of the gas is V  A y, which leads to the following definition:

The work W done on a gas at constant pressure is given by

[12.1]

where P is the pressure throughout the gas and V is the change in volume

of the gas during the process.

If the gas is compressed as in Active Figure 12.1b,V is negative and the work

done on the gas is positive If the gas expands,V is positive and the work done on the gas is negative The work done by the gas on its environment, Wenv , is simply the negative of the work done on the gas In the absence of a change in volume, the work is zero.

W  P V

W  F y  PA y

ACTIVE FIGURE 12.1

(a) A gas in a cylinder occupying a

volume V at a pressure P (b) Pushing

the piston down compresses the gas.

Log into PhysicsNow at http://

physics.brookscole.com/ecpand

go to Active Figure 12.1 to move the piston and see the resulting work done on the gas.

y

P

(a)

A V

(b)

Checkpoint 12.1

True or False: When a gas in a container is kept at constant creased, the work done on the gas is negative.

□

WebAssign

 Active Examples build a bridge between

practice and homework

To help students make the leap from practice to

home-work, all in-text Worked Examples become Active

Examples—algorithmic versions of the in-text Worked

Examples Students are given hints and feedback specific

to their answer to help them master the concept in the

Worked Example And to help build their problem-solving

confidence, students are also provided with a slightly more

difficult follow-up problem.

Goal Apply the definition of work at constant pressure.

Problem In a system similar to that shown in Active Figure 12.1, the gas in the cylinder is at a pressure of 1.01  10 5 Pa and the piston has an area of 0.100 m 2 As energy is slowly added to the gas by heat, the piston is

pushed up a distance of 4.00 cm Calculate the work done by the expanding gas on the surroundings, Wenv , assuming the pressure remains constant.

Strategy The work done on the environment is the negative of the work done on the gas given in Equation 12.1 Compute the change in volume and multiply by the pressure.

Solution

Find the change in volume of the gas, V, which is the cross-sectional area times the displacement :  4.00  10 3 3

V  A y  (0.100 m2 )(4.00  10 2 m)

Multiply this result by the pressure, getting the work the

gas does on the environment, Wenv :

Wenv P V  (1.01  105 Pa)(4.00  10 3m3 )

 404 J

Remark The volume of the gas increases, so the work done on the environment is positive The work done on the

system during this process is W  404 J The energy required to perform positive work on the environment must come from the energy of the gas (See the next section for more details.)

Exercise 12.1

Gas in a cylinder similar to Figure 12.1 moves a piston with area 0.20 m 2 as energy is slowly added to the system If 2.00  10 3 J of work is done on the environment and the pressure of the gas in the cylinder remains constant at 1.01  10 5 Pa, find the displacement of the piston.

Answer 9.90  10 2m

 Conceptual Questions

A selection of Conceptual Questions

allows students to test themselves on

text concepts The Applying Physics

exam-ples from the text serve as models for

stu-dents when Conceptual Questions are

assigned in Enhanced WebAssign and

show how the concepts can be applied to understanding the physical world Found at

the end of every chapter, the Conceptual Questions are ideal for initiating classroom

discussions Answers to odd-numbered

Conceptual Questions are located in the

answer section at the end of the book.

 Quick Quizzes

Quick Quiz questions are

included throughout each

chap-ter to provide opportunities for

students

to test their understanding

of the physical concepts just

presented in the text All of the

Quick Quizzes in this edition

have been cast in an objective

format, including multiple

choice, true/false, and ranking.

They are available to be

assigned through Enhanced

WebAssign.

 End-of-chapter Problems

Serway’s physics texts are renowned for their outstanding collection of end-of- chapter problems For the convenience

of generating assignments, every

end-of-chapter problem is available in Enhanced

WebAssign, most providing hints and

feedback There are three levels of lems, graded according to their difficulty All problems have been carefully worded and have been checked for clarity and accuracy

prob-Three engines operate between reservoirs separated in temperature by 300 K The

reservoir temperatures are as follows:

ronment that promotes conceptual understanding

For Audience Response Systems

Available exclusively for higher education from our

partner-ship with Turning Technologies, JoinIn ™is the easiest way

to turn your lecture hall into a personal, fully interactive

experience for your students! JoinIn allows you to

trans-form your classroom and assess your students’ progress

with instant in-class quizzes and polls Our exclusive

agreement to offer TurningPoint ®software lets you pose

book-specific questions and display students’ answers

seamlessly within the Microsoft®PowerPoint®slides of

your own lecture, in conjunction with the “clicker” hardware

of your choice Enhance how your students interact with

you, your lecture, and each other

JoinIn on TurningPoint:

 Works from within Microsoft ® PowerPoint ®

 Can work with any infrared or radio

frequency keypad system: ResponseCard,

EduCue, H-ITT, laptops

 Is seamlessly compatible with WebCT ® ,

Blackboard ® , and iLrn ™

 Handles special characters such as mathematical

and scientific notation

 Comes with premium text-specific content from

Essentials of College Physics

Active Figure questions allow you to poll your students

based on their interpretations of animated simulations

And, for more advanced audience response polling,

exclu-sive Assessing to Learn in the Classroom questions,

devel-oped at the University of Massachusetts-Amherst, focus on

the most important and challenging concepts, allowing you

to pinpoint exactly where students are facing challenges in

logic

Contact your local Thomson representative to learn

more about JoinIn and our infrared and radio-frequency

hardware solutions, or visit http://www.turningpoint.

thomsonlearningconnections.com.

Quick Quiz questions from the text are included

in the program, providing you with the nity to quickly test students’ basic understand-ing of physics concepts and principles All of

opportu-the Quick Quizzes are cast in an objective

for-mat, including multiple choice, true/false, andranking

x

Welcome to your MCAT Test Preparation Guide

The MCAT Test Preparation Guide makes your copy of Essentials of College Physics the most comprehensive

MCAT study tool and classroom resource in introductory physics The grid, which begins below and continues on

the next two pages, outlines twelve concept-based study courses for the physics part of your MCAT exam Use it to

prepare for the MCAT, class tests, and your homework assignments

Vectors

between vectors, and magnitudes

dimensions, to calculate speed and velocity,

centripetal acceleration, and acceleration in

free fall problems

Laws, to calculate resultant forces, and weight

impulse, center of gravity, and torque

kinetic energy, potential energy, and power

waves, to calculate basic properties of waves,properties of springs, and properties ofpendulums

density, specific gravity, and flow rates

waves, to calculate properties of waves, the speed

of sound, Doppler shifts, and intensity

lenses, to calculate the angles of reflection, to use

the index of refraction, and to find focal lengths

the electric field, the electrostatic force, and the

current, resistance, voltage, power, and energy,and to use circuit analysis

understand decay processes and nuclear reactions

To our wives, children, grandchildren, and relatives who have provided

so much love, support, and understanding through the years, and

to the students for whom this book

was written.



1 Introduction 1

2 Motion in One Dimension 18

3 Vectors and Two-Dimensional Motion 41

4 The Laws of Motion 61

5 Energy 90

6 Momentum and Collisions 124

7 Rotational Motion and the Law of Gravity 147

8 Rotational Equilibrium and Rotational Dynamics 174

9 Solids and Fluids 204

10 Thermal Physics 246

11 Energy in Thermal Processes 272

12 The Laws of Thermodynamics 297

13 Vibrations and Waves 327

14 Sound 354

15 Electric Forces and Electric Fields 387

16 Electrical Energy and Capacitance 413

17 Current and Resistance 445

18 Direct-Current Circuits 465

19 Magnetism 491

20 Induced Voltages and Inductance 521

21 Alternating Current Circuits and Electromagnetic Waves 547

22 Reflection and Refraction of Light 577

23 Mirrors and Lenses 599

30 Nuclear Energy and Elementary Particles 758

APPENDIX A Mathematics Review A.1

APPENDIX B An Abbreviated Table of Isotopes A.14

APPENDIX C Some Useful Tables A.19

APPENDIX D SI Units A.21

Answers to Checkpoints, Quick Quizzes and Odd-Numbered Conceptual Questions and Problems A.22

Credits C.1

Index I.1

Contents Overview

1.1 Standards of Length, Mass, and Time 1

1.2 The Building Blocks of Matter 3

4.2 Newton’s First Law 62

4.3 Newton’s Second Law 63

4.4 Newton’s Third Law 68

4.5 Applications of Newton’s Laws 69

4.6 Forces of Friction 77

Summary 82

Energy

5.1 Work 90

5.2 Kinetic Energy and the Work – Energy Theorem 94

5.3 Gravitational Potential Energy 97

5.4 Spring Potential Energy 104

5.5 Systems and Energy Conservation 109

5.6 Power 110

5.7 Work Done by a Varying Force 113

Summary 115

Chapter 6

Momentum and Collisions 124

6.1 Momentum and Impulse 124

7.1 Angular Speed and Angular Acceleration 147

7.2 Rotational Motion Under Constant Angular Acceleration 150

7.3 Relations Between Angular and Linear Quantities 151

8.1 Torque 174

8.2 Torque and the Two Conditions for Equilibrium 178

8.3 The Center of Gravity 179

8.4 Examples of Objects in Equilibrium 181

8.5 Relationship Between Torque and Angular Acceleration 183

8.6 Rotational Kinetic Energy 189

9.2 The Deformation of Solids 205

9.3 Density and Pressure 209

9.8 Other Applications of Fluid Dynamics 226

9.9 Surface Tension, Capillary Action, and Viscous Fluid Flow229

10.1 Temperature and the Zeroth Law of Thermodynamics 246

10.2 Thermometers and Temperature Scales 247

10.3 Thermal Expansion of Solids and Liquids 251

10.4 Macroscopic Description of an Ideal Gas 257

10.5 The Kinetic Theory of Gases 262

Summary 267

Chapter 11

Energy in Thermal Processes 272

11.1 Heat and Internal Energy 272

The Laws of Thermodynamics297

12.1 Work in Thermodynamic Processes 297

12.2 The First Law of Thermodynamics 300

12.3 Heat Engines and the Second Law of Thermodynamics 309

13.2 Comparing Simple Harmonic Motion

with Uniform Circular Motion 331

13.3 Position, Velocity, and Acceleration as a Function of Time 334

13.4 Motion of a Pendulum 337

13.5 Damped Oscillations 340

13.6 Waves 340

13.7 Frequency, Amplitude, and Wavelength 343

13.8 The Speed of Waves on Strings 344

14.1 Producing a Sound Wave 354

14.2 Characteristics of Sound Waves 354

14.3 The Speed of Sound 356

14.4 Energy and Intensity of Sound Waves 358

14.5 Spherical and Plane Waves 361

14.6 The Doppler Effect 363

14.7 Interference of Sound Waves 367

14.8 Standing Waves 369

14.9 Forced Vibrations and Resonance 373

14.10 Standing Waves in Air Columns 374

Electric Forces and Electric Fields 387

15.1 Properties of Electric Charges 387

15.2 Insulators and Conductors 388

15.3 Coulomb’s Law 390

15.4 The Electric Field 394

15.5 Electric Field Lines 398

15.6 Conductors in Electrostatic Equilibrium 400

15.7 Electric Flux and Gauss’s Law 402

Summary 407

Chapter 16

Electrical Energy and Capacitance413

16.1 Potential Difference and Electric Potential 413

16.2 Electric Potential and Potential Energy Due to Point Charges420

16.3 Potentials and Charged Conductors 422

16.4 Equipotential Surfaces 424

16.5 Capacitance 424

16.6 The Parallel-Plate Capacitor 425

16.7 Combinations of Capacitors 427

16.8 Energy Stored in a Charged Capacitor 433

16.9 Capacitors with Dielectrics 435

Summary 439

Chapter 17

Current and Resistance445

17.1 Electric Current 445

17.2 A Microscopic View: Current and Drift Speed 447

17.3 Current and Voltage Measurements in Circuits 449

17.4 Resistance and Ohm’s Law 450

17.5 Resistivity 451

17.6 Temperature Variation of Resistance 453

17.7 Superconductors 455

17.8 Electrical Energy and Power 456

17.9 Electrical Activity in the Heart 458

19.3 Magnetic Force on a Current-Carrying Conductor 496

19.4 Torque on a Current Loop and Electric Motors 499

19.5 Motion of a Charged Particle in a Magnetic Field 502

19.6 Magnetic Field of a Long, Straight Wire and

Ampère’s Law 505

19.7 Magnetic Force Between Two Parallel Conductors 507

19.8 Magnetic Fields of Current Loops and Solenoids 509

19.9 Magnetic Domains 512

Summary 513

Chapter 20

Induced Voltages and Inductance 521

20.1 Induced emf and Magnetic Flux 521

20.2 Faraday’s Law of Induction 523

21.9 Hertz’s Confirmation of Maxwell’s Predictions 562

21.10 Production of Electromagnetic Waves by an Antenna563

21.11 Properties of Electromagnetic Waves 564

21.12 The Spectrum of Electromagnetic Waves568

Summary 570

Part 5: Light and Optics

Chapter 22

Reflection and Refraction of Light577

22.1 The Nature of Light 577

22.2 Reflection and Refraction 578

22.3 The Law of Refraction 582

22.4 Dispersion and Prisms 585

23.2 Images Formed by Spherical Mirrors 601

23.3 Convex Mirrors and Sign Conventions 603

23.4 Images Formed by Refraction 608

24.1 Conditions for Interference 627

24.2 Young’s Double-Slit Experiment 628

24.3 Change of Phase Due to Reflection 631

24.4 Interference in Thin Films 632

24.5 Diffraction 636

24.6 Single-Slit Diffraction 638

Contents xix

24.7 The Diffraction Grating 640

24.8 Polarization of Light Waves 642

25.3 The Simple Magnifier 658

25.4 The Compound Microscope 660

26.2 The Speed of Light 673

26.3 Einstein’s Principle of Relativity 675

26.4 Consequences of Special Relativity 675

27.1 Blackbody Radiation and Planck’s Hypothesis 693

27.2 The Photoelectric Effect and the Particle Theory of Light 695

27.3 X-Rays 698

27.4 Diffraction of X-Rays by Crystals 699

27.5 The Compton Effect 701

27.6 The Dual Nature of Light and Matter 703

27.7 The Wave Function 706

27.8 The Uncertainty Principle 707

28.3 The Bohr Model 715

28.4 Quantum Mechanics and the Hydrogen Atom 720

28.5 The Exclusion Principle and the Periodic Table 723

30.3 Elementary Particles and the Fundamental Forces 764

30.4 Positrons and Other Antiparticles 765

30.5 Classification of Particles 766

30.6 Conservation Laws 767

30.7 The Eightfold Way 770

30.8 Quarks and Color 770

30.9 Electroweak Theory and the Standard Model 772

30.10 The Cosmic Connection773

30.11 Problems and Perspectives775

Raymond A Serway received his doctorate at Illinois Institute of Technology and is

Professor Emeritus at James Madison University In 1990, he received the MadisonScholar Award at James Madison University, where he taught for 17 years Dr Serwaybegan his teaching career at Clarkson University, where he conducted research andtaught from 1967 to 1980 He was the recipient of the Distinguished Teaching Award

at Clarkson University in 1977 and of the Alumni Achievement Award from UticaCollege in 1985 As Guest Scientist at the IBM Research Laboratory in Zurich,Switzerland, he worked with K Alex Müller, 1987 Nobel Prize recipient Dr Serwayalso was a visiting scientist at Argonne National Laboratory, where he collabo-

rated with his mentor and friend, Sam Marshall In addition to Essentials of College Physics, Dr Serway is the co-author of College Physics, Seventh Edition; Physics for Scientists and Engineers, Sixth Edition; Principles of Physics, Fourth Edition; and Modern Physics, Third Edition He also is the author of the high-school textbook Physics, published by Holt, Rinehart, & Winston In addition, Dr Serway has published

more than 40 research papers in the field of condensed matter physics and has given more than 70 presentations at professional meetings Dr Serway and his wifeElizabeth enjoy traveling, golfing, and spending quality time with their four childrenand seven grandchildren

Chris Vuille is an associate professor of physics at Embry-Riddle Aeronautical

University, Daytona Beach, Florida, the world’s premier institution for aviation highereducation He received his doctorate in physics at the University of Florida in 1989,moving to Daytona after a year at ERAU’s Prescott, Arizona campus While he hastaught courses at all levels, including post-graduate, his primary interest has been thedelivery of introductory physics He has received several awards for teaching excel-lence, including the Senior Class Appreciation Award (three times) He conductsresearch in general relativity and quantum theory, and was a participant in the JOVEprogram, a special three-year NASA grant program during which he studied neutron

stars In addition to Essentials of College Physics, he is a co-author of Serway/Faughn’s College Physics, Seventh Edition His work has appeared in a number of scientific jour- nals, and he has been a featured science writer in Analog Science Fiction/Science Fact

magazine Dr Vuille enjoys tennis, lap swimming, guitar and classical piano, and is aformer chess champion of St Petersburg and Atlanta In his spare time he writes sci-ence fiction and goes to the beach His wife, Dianne Kowing, is an optometrist for

a local VA clinic Teen daughter Kira Vuille-Kowing, a student at Embry-Riddle nautical University, is an accomplished swimmer, violinist, and mall shopper He hastwo sons, fourteen-year-old Christopher, a cellist and sailing enthusiast, and five-year-old James, master of tinkertoys

Aero-About the Authors

Essentials of College Physics is designed for a one-year course in introductory physics for

stu-dents majoring in biology, the health professions, and other disciplines such as

environ-mental, earth, and social sciences The mathematical techniques used in this book include

algebra, geometry, and trigonometry, but not calculus.

While remaining comprehensive in its coverage of physics concepts and techniques,

Essentials is shorter than many other books at this level, resulting in a more streamlined

pre-sentation In preparing the text, the authors sought to reduce optional topics and figures

while being careful to retain the essential knowledge needed by today’s students In addition,

increased attention was paid to developing conceptual and mathematical skills through the

new Checkpoint and Math Focus features The mathematical appendix has been written so that

students can immediately see the physical context in which the mathematical concepts and

techniques are used.

The textbook covers all the standard topics in classical and modern physics: mechanics,

fluid dynamics, thermodynamics, wave motion and sound, electromagnetism, optics,

relativ-ity, quantum physics, atomic physics, nuclear and particle physics, ending with an

introduc-tion to cosmology Emphasis remains on facilitating the understanding of basic concepts and

principles, bolstered by the thorough presentation of the underlying mathematics By

focus-ing on fundamentals, Essentials of College Physics gives students the knowledge and tools they

need to further advance in their chosen fields.

TEXTBOOK FEATURES

Most instructors would agree that the textbook assigned in a course should be the student’s

primary guide for understanding and learning the subject matter Furthermore, the textbook

should be easily accessible and written in a style that facilitates instruction and learning With

this in mind, we have included many pedagogical features that are intended to enhance the

textbook’s usefulness to both students and instructors These features are as follows:

Pedagogical Features

■ Examples All in-text worked examples are presented in a two-column format to better aid

student learning and to help reinforce physical concepts Special care has been taken to

present a range of levels within each chapter’s collection of worked examples, so that

stu-dents are better prepared to solve the end-of-chapter problems The examples are set off

from the text for ease of location and are given titles to describe their content All worked

examples now include the following parts:

(a) Goal Describes the physical concepts being explored within the worked example.

(b) Problem Presents the problem itself.

(c) Strategy Helps students analyze the problem and create a framework for working out

the solution.

(d) Solution Presented using a two-column format that gives the explanation for each

step of the solution in the left-hand column, while giving each accompanying

math-ematical step in the right-hand column This layout facilitates matching the idea with

its execution, and helps students learn how to organize their work Another benefit:

students can easily use this format as a training tool, covering up the solution on the

right and solving the problem using the comments on the left as a guide.

(e) Remarks Follow each solution, and highlight some of the underlying concepts and

methodology used in arriving at a correct solution In addition, the remarks are often

used to put the problem into a larger, real world context.

(f) Exercise/Answer Every worked example is followed immediately by exercises with

answers These exercises allow the students to reinforce their understanding by

work-ing a similar or related problem, the answers givwork-ing them instant feedback At the

option of the instructor, the exercises can also be assigned as homework Students

who work through these exercises on a regular basis will find the end-of-chapter

prob-lems less intimidating.

■ In many chapters, one or two examples combine new concepts with previously studied

con-cepts This not only reviews prior material, but also integrates different concepts, showing

how they work together to enhance our understanding of the physical world.

■ Math Focus Math is often a stumbling block for physics students at the first-year level, so

a new pedagogical tool has been introduced to help students overcome this hurdle Each

Math Focus box develops mathematical methods important to a given area of physics, or

xxi

Preface

points out a critical mathematical fact or technique that is often overlooked In general, the theory is briefly described, followed by one or two short examples illustrating the application of the theory The Math Focus boxes further the Serway tradition of empha- sizing the importance of sound mathematical understanding in a physical context.

■ Physics-Oriented Math Appendix By approaching the mathematics first and then ing each quantitative concept to a tangible physics application, the math appendix found

apply-at the back of the book (Appendix A) is designed to help students make a clear tion between their mathematical skills and the physics concepts.

connec-■ Checkpointsare relatives of the Quick Quizzes, but differ in thrust The idea is to engage students during their reading by asking simple questions based on the text, often in a true- false format One type of Checkpoint may help students understand how certain physical quantities depend on others, while another may test whether students have grasped a par- ticular concept The Checkpoints are designed to give quick feedback, reinforcement of basic concepts, and a feel for the relationships between physical quantities Answers to all Checkpoint questions are found at the end of the textbook.

■ Quick Quizzes Quick Quizzes provide students with opportunities to test their tual understanding of the physical concepts presented The questions require students to make decisions on the basis of sound reasoning, and some of them have been written to help students overcome common misconceptions All of the Quick Quizzes have been cast in an objective format, including multiple choice, true-false, and ranking Answers to all Quick Quiz questions are found at the end of the textbook, while answers with detailed

concep-explanations are provided in the Instructor’s Manual.

■ Vectorsare denoted in bold face with arrows over them (for example, ), making them easier to recognize.

■ Problem-Solving Strategies A general strategy to be followed by the student is outlined at the end of Chapter 1 and provides students with a structured process for solving prob- lems In most chapters, more specific strategies and suggestions are included for solving the types of problems featured in both the worked examples and end-of-chapter prob- lems This feature, highlighted by a surrounding box, is intended to help students iden- tify the essential steps in solving problems and increases their skills as problem solvers.

■ Tipsare placed in the margins of the text and address common student misconceptions and situations in which students often follow unproductive paths.

■ End-of-Chapter Problems and Conceptual Questions An extensive set of problems is included at the end of each chapter Answers to odd-numbered problems are given at the end of the book For the convenience of both the student and instructor, about two-thirds

of the problems are keyed to specific sections of the chapter The remaining problems, labeled “Additional Problems,” are not keyed to specific sections There are three levels

of problems that are graded according to their difficulty Straightforward problems are numbered in black, intermediate level problems are numbered in blue , and the most challenging problems are numbered in magenta

■ Biomedical Applications For biology and premed students, icons point the way to ious practical and interesting applications of physical principles to biology and medicine Where possible, an effort was made to include more problems that would be relevant to these disciplines.

var-■ MCAT Test Preparation Guide For students planning on taking the MCAT, a special guide in the preface outlines key concepts and directed review activities from the text and

PhysicsNow™ program to help get students up to speed for the physics part of the exam.

■ Applying Physicsprovide students with an additional means of reviewing concepts sented in that section Some Applying Physics examples demonstrate the connection between the concepts presented in that chapter and other scientific disciplines These examples also serve as models for students when assigned the task of responding to the Conceptual Questions presented at the end of each chapter.

pre-■ Summary The Summary is organized by individual chapter heading for ease of reference.

■ PhysicsNow™ and Essentials of College Physics were built in concert to provide a seamless,

integrated Web-based learning system Throughout the text, the icon

directs readers to media-enhanced activities at the PhysicsNow™ Web site The precise

page-by-page integration means professors and students will spend less time flipping through pages and navigating Web sites for useful exercises For an online demonstration

of PhysicsNow™, please visit: http://physics.brookscole.com/ecp.

■ Active Figures Many diagrams from the text have been animated to form Active Figures,

part of the PhysicsNow™ integrated Web-based learning system and available for lecture

projection on the Instructor’s Multimedia Manager CD-ROM By visualizing phenomena and processes that cannot be fully represented on a static page, students greatly increase their conceptual understanding Students also have the opportunity to change variables

to see the effects, conduct suggested explorations of the principles involved in the figure, and take and receive feedback on quizzes related to the figure Active Figures are easily identified by their red figure legend and icon.

■ Marginal Notes Comments and notes appearing in the margin can be used to locate important statements, equations, and concepts in the text.

v

:

Preface xxiii

■ Important Statements and Equations Most important statements and definitions are set

in boldface type or are highlighted with a background screen for added emphasis and ease

of review Similarly, important equations are highlighted with a tan background screen to

facilitate location.

■ Writing Style To facilitate rapid comprehension, we have attempted to write the book in

a style that is clear, logical, relaxed, and engaging The informal and relaxed writing style

is intended to increase reading enjoyment New terms are carefully defined, and we have

avoided the use of jargon.

■ Units The international system of units (SI) is used throughout the text The U.S

cus-tomary system of units is used only to a limited extent in the chapters on mechanics and

thermodynamics.

■ Significant Figures Significant figures in both worked examples and end-of-chapter

prob-lems have been handled with care Most numerical examples and probprob-lems are worked out

to either two or three significant figures, depending on the accuracy of the data provided.

Intermediate results presented in the examples are rounded to the proper number of

significant figures, and only those digits are carried forward.

TEACHING OPTIONS

This book contains more than enough material for a one-year course in introductory physics.

This serves two purposes First, it gives the instructor more flexibility in choosing topics for

a specific course Second, the book becomes more useful as a resource for students On the

average, it should be possible to cover about one chapter each week for a class that meets

three hours per week Those sections, examples, and end-of-chapter problems dealing with

applications of physics to life sciences are identified with the DNA icon We offer the

fol-lowing suggestions for shorter courses for those instructors who choose to move at a slower

pace through the year.

Option A:If you choose to place more emphasis on contemporary topics in physics, you

should consider omitting all or parts of Chapter 8 (Rotational Equilibrium and Rotational

Dynamics), Chapter 21 (Alternating Current Circuits and Electromagnetic Waves), and

Chapter 25 (Optical Instruments).

Option B:If you choose to place more emphasis on classical physics, you could omit all or

parts of Part VI of the textbook, which deals with special relativity and other topics in 20th

century physics.

The Instructor’s Manual offers additional suggestions for specific sections and topics that

may be omitted without loss of continuity if time presses.

ANCILLARIES

The most essential parts of the student package are the two-volume Student Solutions Manual

and Study Guide with a tight focus on problem solving and the Web-based PhysicsNow™

learning system Instructors will find increased support for their teaching efforts with new

electronic materials, including online homework support and audience response system

technologies.

STUDENT ANCILLARIES

Thomson Brooks/Cole offers several items to supplement and enhance the classroom

expe-rience One or more of these ancillaries may be shrink-wrapped with the text at a reduced

price:

Student Solutions Manual and Study Guideby John R Gordon, Charles Teague, and Raymond

A Serway Offered in two volumes, this manual features detailed solutions to approximately

20% of the end-of-chapter problems Boxed numbers identify those problems in the

text-book for which complete solutions are found in the manual The manual also features a

skills section, important notes from key sections of the text, and a list of important

equa-tions and concepts Volume 1 (ISBN 0-495-10781-6) contains Chapters 1–14 and Volume 2

(ISBN 0-495-10782-4) contains Chapters 15–30.

PhysicsNow™ is a student-based online tutorial system designed to help

stu-dents identify and strengthen their unique areas of conceptual and quantitative weakness.

The PhysicsNow™ system is made up of three interrelated parts:

■ How much do you know?

■ What do you need to learn?

■ What have you learned?

Students maximize their success by starting with the Pre-Test for the relevant chapter Each Pre-Test is a mix of conceptual and numerical questions After completing the Pre-Test, each student is presented with a detailed Learning Plan The Learning Plan outlines elements to review in the text and Web-based media (Active Figures, Interactive Examples, and Coached Problems) in order to master the chapter’s most essential concepts After working through these materials, students move on to a multiple-choice Post-Test presenting them with ques- tions similar to those that might appear on an exam Results can be e-mailed to instructors PhysicsNow also includes access to vMentor™, an online live-tutoring service, and MathAssist,

an algebra and trigonometry remediation tool.

Students log into PhysicsNow by using an access code (available bundled with the

pur-chase of a new text or via our online bookstore) at http://www.thomsonedu.com.

MCAT Practice Questions for Physicsis the ideal text companion to help students prepare for the MCAT exam This 50-page supplement includes questions written by an MCAT test-prep expert, answers, and explanations for the Physical Sciences section of the exam This is avail- able packaged with new copies of the text at no additional charge Contact your Thomson Representative for details (ISBN 0-534-42379-5)

INSTRUCTOR ANCILLARIES

The following ancillaries are available to qualified adopters Please contact your local Thomson Brooks/Cole sales representative for details Ancillaries offered in two volumes are split as follows: Volume 1 contains Chapters 1–14 and Volume 2 contains Chapters 15–30.

Lecture Tools

Multimedia Manager Instructor’s Resource CD This easy-to-use lecture tool allows you to quickly assemble art, photos, and multimedia with notes to create fluid lectures The CD-ROM set (Volume 1, Chapters 1–14; Volume 2, Chapters 15–30) includes a database of animations, video clips, and digital art from the text, as well as PowerPoint lectures and editable elec-

tronic files of the Instructor’s Solutions Manual and Test Bank You’ll also find additional

con-tent from the textbook like the Quick Quizzes and Conceptual Questions.

Audience Response Hardware and Content Our exclusive agreement to offer TurningPoint ®

software lets you pose text-specific questions and display students’ answers seamlessly within the Microsoft ® PowerPoint ® slides of your own lecture, in conjunction with the “clicker” hard- ware of your choice Book-specific content includes all of the “Quick Quizzes,” “Checkpoints,” and “Active Figures.” New “Assessing to Learn in the Classroom” questions, developed by the University of Massachusetts at Amherst, take response system content to the next level, allow- ing you to more exactly pinpoint where students may be facing challenges in logic The text can also be bundled with ResponseCard “clickers,” using either an infrared or radio fre- quency solution depending on your unique lecture hall needs Contact your local Thomson Brooks/Cole representative to learn more.

Class Preparation

Instructor’s Solutions Manual(Volume 1 ISBN: 0-495-10785-9; Volume 2 ISBN: 0-495-10787-5)

by Charles Teague Available in two volumes, this manual consists of complete solutions to all the problems in the text, answers to the even-numbered problems and conceptual ques- tions, and full answers with explanations to the Quick Quizzes It is provided both on the Instructor’s Multimedia Manager CD-ROM and in print form for the instructor who does not have access to a computer.

cate Test Bank pages for distribution to students.

ExamView Computerized Testing CD-ROM(ISBN: 0-495-10789-1) The questions in the Test Bank are also available in electronic format with complete answers through ExamView® Create, deliver, and customize tests and study guides (both print and online) in minutes with this easy-to-use assessment and tutorial system ExamView offers both a Quick Test Wizard and

Preface xxv

an Online Test Wizard that guide you step-by-step through the process of creating tests, while

the unique “WYSIWYG” capability allows you to see the test you are creating on the screen

exactly as it will print or display online You can build tests of up to 250 questions using up to

12 question types Using ExamView’s complete word processing capabilities, you can enter an

unlimited number of new questions or edit the existing questions from the preloaded printed

test bank.

Online Homework

WebAssign: A Web-Based Homework System WebAssign is the most utilized homework system

in physics, allowing instructors to securely create and administer homework assignments in an

interactive online environment An enhanced version of WebAssign is available for Essentials

of College Physics Instructors can choose to assign any end-of-chapter problem, conceptual

question, quick quiz, worked example, or active figure simulation from the text Every

prob-lem includes answer-specific feedback, many with probprob-lem-specific hints and simulations, to

help guide your students to content mastery Take a look at this new innovation from the most

trusted name in physics homework by visiting http://physics.brookscole.com/ecp.

WebCT and Blackboard/Now Integration Integrate the conceptual testing and multimedia

tutorial features of PhysicsNow™ within your familiar WebCT or Blackboard environment by

packaging the text with a special access code You can assign the PhysicsNow™ materials and

have the results flow automatically to your WebCT or Blackboard grade book, creating a

robust online course Students access PhysicsNow™ via your WebCT or Blackboard course,

without using a separate user name or password Contact your local Thomson Brooks/Cole

representative to learn more.

UT Austin Homework Service Details about and a demonstration of this service are available

at https://hw.utexas.edu/bur/demo.html.

Laboratory Manual

Physics Laboratory Manual,second edition by David Loyd This laboratory manual includes

over 47 labs The Instructor’s Manual includes teaching hints, answers to selected questions

from the student laboratory manual, and a post-laboratory quiz with short answers and essay

questions The author has also included a list of the suppliers of scientific equipment and a

summary of the equipment needed for all the experiments in the manual.

ACKNOWLEDGEMENTS

In preparing this textbook, we were fortunate to receive advice from a number of professors

regarding how to best streamline the presentation for a one-year course We offer our thanks

to those professors:

Elise Adamson, Wayland Baptist University; Kyle Altmann, Elon University; John Altounji, Los

Angeles Valley College; James Andrews, Youngstown State University; Kenneth W Bagwell, Mississippi

Gulf Coast Community College; Natalie Batalha, San Jose State University; Brian Beecken, Bethel

University; Kurt Behpour, California Polytechnic Tate University, San Luis Obispo; Charles Benesh,

Wesleyan College; Raymond Bigliani, Farmingdale State University of New York; Earl Blodgett,

Univer-sity of Wisconsin-River Falls; Donald E Bowen, Stephen F Austin State UniverUniver-sity; Wayne Bresser,

Northern Kentucky University; Melissa W Bryan, Darton College; Daniel Bubb, Seton Hall University;

Richard L Cardenas, St Mary’s University; Andrew Carmichael, University of Connecticut; Cliff

Castle, Jefferson College; Marco Cavaglia, University of Mississippi; Eugene Chaffin, Bob Jones

Uni-versity; Marvin Champion, Georgia Military College; Anastasia Chopelas, University of Washington,

Seattle; Greg Clements, Midland Lutheran College; John Coffman, Florida College; Tom Colbert,

Augusta State University; Cpt David J Crilly, New Mexico Military Institute; Doug Davis, Eastern

Illinois University; Lawrence Day, Utica College; John Dayton, American International College; Sandee

Desmarais, Daytona Beach Community College; Mariam Dittman, Georgia Perimeter College; David

Donnelly, Texas State University; David W Donovan, Northern Michigan University; Edward Dressler,

Pennsylvania State University, Abington; William W Eidson, Webster University; Steve Ellis, University

of Kentucky; Shamanthi Fernando, Northern Kentucky University; Peter M Fichte, Coker College;

Allen P Flora, Hood College; Dolen Freeouf, Southeast Community College; Michael Frey, California

State University, Long Beach; Tony Gaddis, Haywood Community College; Ticu Gamalie, Arkansas State

University-Beebe; Ralph C Gatrone, Virginia State University; John P Golben, Calhoun Community

College; George Goth, Skyline College; Richard Grant; Morris Greenwood, San Jacinto College; David

Groh, Gannon University; Allen Grommet, East Arkansas Community College; Mike Gunia, DeVry

University; Israel Gurfinkiel, Rutgers University; Bill Harris, Mountain Empire Community College;

Joseph Harrison, University of Alabama at Birmingham; Frank Hartranft, University of Nebraska at

Omaha; Dennis Hawk, Navarro College; George Hazelton, Chowan College; Rhett Herman, Radford University; Gerald E Hite, Texas A & M University at Galveston; Jeffrey Lynn Hopkins, Midlands Technical College; Herbert Jaeger, Miami University; Catherine Jahncke, St Lawrence University; Robert Keefer, Lake Sumter Community College; Charles N Keller, Cornerstone University; Andrew Kerr, University of Findlay; Kinney H Kim, North Carolina Central University; Tiffany Landry, Folsom Lake College; Eric Lane, University of Tennessee Chattanooga; Gregory Lapicki, East Carolina Univer- sity; Lee LaRue, Paris Junior College; David Lawing, Macon State College; Todd Leif, Cloud County Community College; Andy Leonardi, University of South Carolina Upstate; Peter Leung, Portland State University; John Leyba, Newman University; Ntungw Maasha, Coastal Georgia Community Col- lege; Helen Major, Lincoln University; Kingshuk Majumdar, Berea College; Frank Mann, Emmanuel College; David Matzke, University of Michigan-Dearborn; Tom McGovern, Pratt Community College;

E R McMullen, Delgado Community College; William Miles, East Central Community College; Anatoly Miroshnichenko, University of Toledo; David J Naples, St Edward’s University; Alex Neubert, State University of New York College of Technology at Canton; Paul Nienaber, St Mary’s University; Martin Nikolo, St Louis University; Christine O’Leary, Wallace State Community College; John Olson, Metro- politan State Univ; Paige Ouzts, Lander University; Karur Padmanabhan, Wayne State University; John Peters, Stanly Community College; Robert Philbin, Trinidad State Junior College; Alberto Pinkas, New Jersey City University; Amy Pope, Clemson University; Promod Pratap, University of North Caro- lina at Greensboro; Kathy Qin, Morton College; Ken Reyzer, San Diego City College; Herbert Ringel, Borough of Manhattan Community College; John Rollino, Rutgers University-Newark; Michael Rulison, Oglethorpe University; Marylyn Russ, Marygrove College; Ron Sanders, Southern Union State Community College; Peter Schoch, Sussex County Community College; Joseph Schroeder, Olivet Nazarene Univer- sity; Anthony Scioly, Siena Heights University; Rony Shahidain, Kentucky State University; M Sharifian, Compton College; Peter Sheldon, Randolph-Macon Woman’s College; A Shiekh, Dine College; Dave Slimmer, Lander University; Xiangning Song, Richland College; Stuart Swain, University of Maine

at Machias; Hooshang Tahsiri, California State University, Long Beach; Hasson Tavossi, Mesa State College; Rajive Tiwari, Belmont Abbey College; Valentina Tobos, Lawrence Technological University; Luisito Tongson, Central Connecticut State University; Dale M Trapp, Concordia University; James Tressel, Massasoit Community College; Andra Troncalli, Austin College; Frank Trumpy, Des Moines Area Community College; David Vakil, El Camino College; Pedro Valadez, University of Wisconsin-Rock County; Xiujuan Wang, Foothill College; Gregory White, Northwest College; Tom Wilbur, Anne Arundel Community College; Gail Wyant, Cecil College.

We were also guided by the expertise of the many people who have reviewed previous

edi-tions of College Physics We wish to acknowledge the following reviewers and express our

sin-cere appreciation for their helpful suggestions, criticism, and encouragement:

Gary B Adams, Arizona State University; Marilyn Akins, Broome Community College; Ricardo Alarcon, Arizona State University; Albert Altman, University of Lowell; John Anderson, University

of Pittsburgh; Lawrence Anderson-Huang, University of Toledo; Subhash Antani, Edgewood College; Neil W Ashcroft, Cornell University; Charles R Bacon, Ferris State University; Dilip Balamore, Nassau Community College; Ralph Barnett, Florissant Valley Community College; Lois Barrett, Western Washington University; Natalie Batalha, San Jose State University; Paul D Beale, University of Colorado

at Boulder; Paul Bender, Washington State University; David H Bennum, University of Nevada at Reno; Ken Bolland, Ohio State University; Jeffery Braun, University of Evansville; John Brennan, University of Central Florida; Michael Bretz, University of Michigan, Ann Arbor; Michael E Browne, University of Idaho; Joseph Cantazarite, Cypress College; Ronald W Canterna, University of Wyoming; Clinton M Case, Western Nevada Community College; Neal M Cason, University of Notre Dame; Kapila Clara Castoldi, Oakland University; Roger W Clapp, University of South Florida; Giuseppe Colaccico, University of South Florida; Lattie F Collins, East Tennessee State University; Lawrence B Colman, University of California, Davis; Andrew Cornelius, University of Nevada, Las Vegas; Jorge Cossio, Miami Dade Community College; Terry T Crow, Mississippi State College; Yesim Darici, Florida International University; Stephen D Davis, University of Arkansas at Little Rock; John DeFord, University of Utah; Chris J DeMarco, Jackson Community College; Michael Dennin, University of California, Irvine; N John DiNardo, Drexel University; Steve Ellis, University of Kentucky; Robert J Endorf, University of Cincinnati; Hasan Fakhruddin, Ball State University/The Indiana Academy; Paul Feldker, Florissant Valley Community College; Leonard X Finegold, Drexel University; Emily Flynn; Lewis Ford, Texas A & M University; Tom French, Montgomery County Community College; Albert Thomas Frommhold, Jr., Auburn University; Lothar Frommhold, University of Texas at Austin; Eric Ganz, University of Minnesota; Teymoor Gedayloo, California Polytechnic State University; Simon George, California State University, Long Beach; James R Goff, Pima Community College; Yadin Y Goldschmidt, University of Pittsburgh; John R Gordon, James Madison University; George

W Greenless, University of Minnesota; Wlodzimierz Guryn, Brookhaven National Laboratory; Steve Hagen, University of Florida; Raymond Hall, California State University, Fresno; Patrick Hamill, San Jose State University; James Harmon, Oklahoma State University; Joel Handley; Grant W Hart, Brigham Young University; James E Heath, Austin Community College; Grady Hendricks, Blinn College; Christopher Herbert, New Jersey City University; Rhett Herman, Radford University; John

Ho, State University of New York at Buffalo; Aleksey Holloway, University of Nebraska at Omaha; Murshed Hossain, Rowan University; Robert C Hudson, Roanoke College; Joey Huston, Michigan State University; Fred Inman, Mankato State University; Mark James, Northern Arizona University; Ronald E Jodoin, Rochester Institute of Technology; Randall Jones, Loyola College in Maryland; Drasko Jovanovic, Fermilab; George W Kattawar, Texas A & M University; Joseph Keane,

St Thomas Aquinas College; Frank Kolp, Trenton State University; Dorina Kosztin, University of

Preface xxvii

Missouri–Columbia; Joan P.S Kowalski, George Mason University; Ivan Kramer, University of

Maryland, Baltimore County; Sol Krasner, University of Chicago; Karl F Kuhn, Eastern Kentucky

University; David Lamp, Texas Tech University; Harvey S Leff, California State Polytechnic University;

Joel Levine, Orange Coast College; Michael Lieber, University of Arkansas; Martha Lietz, Niles West

High School; James Linbald, Saddleback Community College; Edwin Lo; Bill Lochslet, Pennsylvania

State University; Rafael Lopez-Mobilia, University of Texas at San Antonio; Michael LoPresto, Henry

Ford Community College; Bo Lou, Ferris State University; Jeffrey V Mallow, Loyola University of

Chicago; David Markowitz, University of Connecticut; Steven McCauley, California State Polytechnic

University, Pomona; Joe McCauley, Jr., University of Houston; Ralph V McGrew, Broome Community

College; Bill F Melton, University of North Carolina at Charlotte; John A Milsom, University of

Arizona; Monty Mola, Humboldt State University; H Kent Moore, James Madison University; John

Morack, University of Alaska, Fairbanks; Steven Morris, Los Angeles Harbor College; Charles W Myles,

Texas Tech University; Carl R Nave, Georgia State University; Martin Nikolo, Saint Louis University;

Blaine Norum, University of Virginia; M E Oakes, University of Texas at Austin; Lewis J Oakland,

University of Minnesota; Ed Oberhofer, Lake Sumter Community College; Lewis O’Kelly, Memphis

State University; David G Onn, University of Delaware; J Scott Payson, Wayne State University; Chris

Pearson, University of Michigan-Flint; Alexey A Petrov, Wayne State University; T.A.K Pillai,

University of Wisconsin, La Crosse; Lawrence S Pinsky, University of Houston; William D Ploughe,

Ohio State University; Patrick Polley, Beloit College; Brooke M Pridmore, Clayton State University;

Joseph Priest, Miami University; James Purcell, Georgia State University; W Steve Quon, Ventura

College; Michael Ram, State University of New York at Buffalo; Kurt Reibel, Ohio State University;

M Anthony Reynolds, Embry-Riddle Aeronautical University; Barry Robertson, Queen’s University;

Virginia Roundy, California State University, Fullerton; Larry Rowan, University of North Carolina,

Chapel Hill; Dubravka Rupnik, Louisiana State University; William R Savage, The University of Iowa;

Reinhard A Schumacher, Carnegie Mellon University; Surajit Sen, State University of New York at

Buffalo; John Simon, University of Toledo; Marllin L Simon, Auburn University; Matthew Sirocky;

Donald D Snyder, Indiana University at Southbend; George Strobel, University of Georgia; Carey E.

Stronach, Virginia State University; Thomas W Taylor, Cleveland State University; Perry A Tompkins,

Samford University; L L Van Zandt, Purdue University; Howard G Voss, Arizona State University;

James Wanliss, Embry-Riddle Aeronautical University; Larry Weaver, Kansas State University; Donald

H White, Western Oregon State College; Bernard Whiting, University of Florida; George A Williams,

The University of Utah; Jerry H Wilson, Metropolitan State College; Robert M Wood, University of

Georgia; Clyde A Zaidins, University of Colorado at Denver

Randall Jones generously contributed several end-of-chapter problems, especially those

of interest to the life sciences Edward F Redish of the University of Maryland graciously

allowed us to use some of his problems from the Activity Based Physics Project as

end-of-chapter problems.

We are extremely grateful to the publishing team at the Brooks/Cole Publishing Company

for their expertise and outstanding work in all aspects of this project In particular, we’d like

to thank Ed Dodd, who tirelessly coordinated and directed our efforts in preparing the

man-uscript in its various stages, and Karoliina Tuovinen, who managed the ancillary program Jane

Sanders, the photo researcher, did a great job finding photos of physical phenomena, Sam

Subity coordinated the building of the PhysicsNow™ Web site, and Rob Hugel helped

trans-late our rough sketches into accurate, compelling art Chris Hall and Teri Hyde also made

numerous valuable contributions Chris provided just the right amount of guidance and vision

throughout the project We thank David Harris, a great team builder with loads of enthusiasm

and an infectious sense of humor.

Finally, we are deeply indebted to our wives and children for their love, support, and

Although physics is relevant to so much in our modern lives, this may not be obvious to

stu-dents in an introductory course In Essentials of College Physics, the relevance of physics to

every-day life is made more obvious by pointing out specific applications in the form of a marginal note Some of these applications pertain to the life sciences and are marked with the DNA icon The list below is not intended to be a complete listing of all the applications of the principles

of physics found in this textbook Many other applications are to be found within the text and especially in the worked examples, conceptual questions, and end-of-chapter problems.

Boxing and brain injury, p 126

Injury to passengers in car collisions,

p 127

Glaucoma testing, p 130

Professor Goddard was right all

along—rockets work in space! p 140

Chapter 7

ESA launch sites, p 153

Geosynchronous orbit and

Testing your car’s antifreeze, p 218

Flight of a golf ball, pp 226 – 227

“Atomizers” in perfume bottles and

paint sprayers, p 227

Vascular flutter and aneurysms, p 227

Lift on aircraft wings, p 227

Home plumbing, p 228

Rocket engines, p 229

Air sac surface tension, p 230

Detergents and waterproofing agents,

p 231

Effect of osmosis on living cells, p 235

Kidney function and dialysis, p 235

Chapter 11

Working off breakfast, pp 273 – 274 Physiology of exercise, p 274 Sea breezes and thermals, p 275 Home insulation, pp 285 – 286 Staying warm in the arctic, pp 286 – 287 Cooling automobile engines, p 288 Algal blooms in ponds and lakes, p 288 Body temperature, p 289

Light-colored summer clothing, p 290 Thermography, p 290

Radiation thermometers, p 290 Thermal radiation and night vision,

p 291

Chapter 12

Refrigerators and heat pumps, p 311

“Perpetual motion” machines, p 316 Human metabolism, pp 319 – 321 Fighting fat, p 321

Chapter 13

Pistons and drive wheels, p 332 Pendulum clocks, p 338 Use of pendulum in prospecting, p 338 Shock absorbers, p 340

Bass guitar strings, p 345

Chapter 14

Medical uses of ultrasound, p 355 Ultrasonic ranging unit for cameras,

p 356 The sounds heard during a storm,

p 357 OSHA noise level regulations, p 361 Connecting your stereo speakers,

p 368 Tuning a musical instrument, p 370 Guitar fundamentals, p 371 Shattering goblets with the voice,

p 373 Structural resonance in bridges and buildings, p 373

Oscillations in a harbor, p 375 Using beats to tune a musical instrument, p 377 The ear, pp 378 – 380

Chapter 15

Lightning rods, p 402 Driver safety during electrical storms, p 402

Chapter 16

Automobile batteries, p 419 Camera flash attachments, p 425 Defibrillators, p 434

Chapter 17

Why do light bulbs fail?, p 457 Electrocardiograms, p 458 Cardiac pacemakers, p 459 Implanted cardioverter defibrillators,

p 460

Chapter 18

Circuit breakers, p 470 Three-way lightbulbs, p 471 Bacterial growth, p 477 Roadway flashers, p 477 Fuses and circuit breakers, p 479 Third wire on consumer appliances,

p 480 Conduction of electrical signals by neurons, pp 481 – 484

Chapter 19

Dusting for fingerprints, p 492 Magnetic bacteria, p 493 Loudspeaker operation, p 498 Electromagnetic pumps for artificial hearts and kidneys, p 498 Electric motors, p 502 Mass spectrometers, p 504 Controlling the electron beam in a television set, p 510

Chapter 20

Ground fault interrupters, p 526 Apnea monitors, p 526 Alternating current generators, p 531 Direct current generators, p 532 Motors, p 534

Chapter 21

Shifting phase to deliver more power,

p 557 Tuning your radio, p 558 Metal detectors in airports, p 558 Long-distance electric power transmission, p 560 Radio-wave transmission, p 563

Applications xxix

Chapter 22

Seeing the road on a rainy night, p 579

Red eyes in flash photographs, p 580

Identifying gases with a spectrometer,

Television signal interference, p 630

Checking for imperfections in optical

Confining electromagnetic waves in a microwave oven, p 645

As a student, it’s important that you understand how to use the book most effectively, and how best to go about learning physics Scanning through the Preface will acquaint you with the various features available, both in the book and online Awareness of your educational resources and how to use them is essential Though physics is challenging, it can be mastered with the correct approach.

HOW TO STUDY

Students often ask how best to study physics and prepare for examinations There’s no ple answer to this question, but we’d like to offer some suggestions based on our own expe- riences in learning and teaching over the years.

sim-First and foremost, maintain a positive attitude toward the subject matter Like learning a language, physics takes time Those who keep applying themselves on a daily basis can expect

to reach understanding Keep in mind that physics is the most fundamental of all natural ences Other science courses that follow will use the same physical principles, so it is impor- tant that you understand and are able to apply the various concepts and theories discussed

sci-in the text.

CONCEPTS AND PRINCIPLES

Students often try to do their homework without first studying the basic concepts It is

essen-tial that you understand the basic concepts and principles before attempting to solve assigned problems You can best accomplish this goal by carefully reading the textbook before you

attend your lecture on the covered material When reading the text, you should jot down those points that are not clear to you Also be sure to make a diligent attempt at answering the questions in the Checkpoints and Quick Quizzes as you come to them in your reading.

We have worked hard to prepare questions that help you judge for yourself how well you understand the material Pay careful attention to the many Tips throughout the text These will help you avoid misconceptions, mistakes, and misunderstandings as well as maximize the efficiency of your time by minimizing adventures along fruitless paths During class, take careful notes and ask questions about those ideas that are unclear to you Keep in mind that few people are able to absorb the full meaning of scientific material after only one reading.

Be sure to take advantage of the features available in the PhysicsNow™ learning system, such

as the Active Figures, Interactive Examples, and Coached Problems Your lectures and tory work supplement your textbook and should clarify some of the more difficult material You should minimize rote memorization of material Successful memorization of passages from the text, equations, and derivations does not necessarily indicate that you understand the fundamental principles.

labora-Your understanding will be enhanced through a combination of efficient study habits, cussions with other students and with instructors, and your ability to solve the problems pre- sented in the textbook Ask questions whenever you feel clarification of a concept is necessary.

dis-STUDY SCHEDULE

It is important for you to set up a regular study schedule, preferably a daily one Make sure you read the syllabus for the course and adhere to the schedule set by your instructor As a general rule, you should devote about two hours of study time for every hour you are in class.

If you are having trouble with the course, seek the advice of the instructor or other students who have taken the course You may find it necessary to seek further instruction from expe- rienced students Very often, instructors offer review sessions in addition to regular class peri- ods It is important that you avoid the practice of delaying study until a day or two before an exam One hour of study a day for fourteen days is far more effective than fourteen hours the day before the exam “Cramming” usually produces disastrous results, especially in sci- ence Rather than undertake an all-night study session just before an exam, briefly review the basic concepts and equations and get a good night’s rest If you feel you need additional help

in understanding the concepts, in preparing for exams, or in problem-solving, we suggest

that you acquire a copy of the Student Solutions Manual and Study Guide that accompanies this

textbook; this manual should be available at your college bookstore.

USE THE FEATURES

You should make full use of the various features of the text discussed in the preface For ple, marginal notes are useful for locating and describing important equations and concepts,

exam-and boldfaced type indicates important statements exam-and definitions Many useful tables are

To the Student

To the Student xxxi

contained in the Appendices, but most tables are incorporated in the text where they are

most often referenced Appendix A is a convenient review of mathematical techniques.

Answers to all Checkpoints and Quick Quizzes, as well as odd-numbered conceptual

ques-tions and problems, are given at the end of the textbook Answers to selected end-of-chapter

problems are provided in the Student Solutions Manual and Study Guide Problem-Solving

Strategies included in selected chapters throughout the text give you additional information

about how you should solve problems The Table of Contents provides an overview of the

entire text, while the Index enables you to locate specific material quickly Footnotes

some-times are used to supplement the text or to cite other references on the subject discussed.

After reading a chapter, you should be able to define any new quantities introduced in

that chapter and to discuss the principles and assumptions used to arrive at certain key

rela-tions The chapter summaries and the review sections of the Student Solutions Manual and

Study Guide should help you in this regard In some cases, it may be necessary for you to refer

to the index of the text to locate certain topics You should be able to correctly associate with

each physical quantity the symbol used to represent that quantity and the unit in which the

quantity is specified Furthermore, you should be able to express each important relation in

a concise and accurate prose statement.

PROBLEM SOLVING

R P Feynman, Nobel laureate in physics, once said, “You do not know anything until you have

practiced.” In keeping with this statement, we strongly advise that you develop the skills

neces-sary to solve a wide range of problems Your ability to solve problems will be one of the main

tests of your knowledge of physics; therefore, you should try to solve as many problems as

pos-sible It is essential that you understand basic concepts and principles before attempting to solve

problems It is good practice to try to find alternate solutions to the same problem For

exam-ple, you can solve problems in mechanics using Newton’s laws, but very often an alternate

method that draws on energy considerations is more direct You should not deceive yourself into

thinking you understand a problem merely because you have seen it solved in class You must

be able to solve the problem and similar problems on your own We have recast the examples

in this book to help you in this regard After studying an example, see if you can cover up the

right-hand side and do it yourself, using only the written descriptions on the left as hints Once

you succeed at that, try solving the example completely on your own Finally, solve the exercise.

Once you have accomplished all this, you will have a good mastery of the problem, its concepts,

and mathematical technique.

The approach to solving problems should be carefully planned A systematic plan is especially

important when a problem involves several concepts First, read the problem several times until

you are confident you understand what is being asked Look for any key words that will help you

interpret the problem and perhaps allow you to make certain assumptions Your ability to

inter-pret a question properly is an integral part of problem solving Second, you should acquire the

habit of writing down the information given in a problem and those quantities that need to be

found; for example, you might construct a table listing both the quantities given and the

quan-tities to be found This procedure is sometimes used in the worked examples of the textbook.

After you have decided on the method you feel is appropriate for a given problem, proceed with

your solution Finally, check your results to see if they are reasonable and consistent with your

initial understanding of the problem General problem-solving strategies of this type are

includ-ed in the text and are highlightinclud-ed with a surrounding box If you follow the steps of this

proce-dure, you will find it easier to come up with a solution and also gain more from your efforts.

Often, students fail to recognize the limitations of certain equations or physical laws in a

particular situation It is very important that you understand and remember the assumptions

underlying a particular theory or formalism For example, certain equations in kinematics

apply only to a particle moving with constant acceleration These equations are not valid for

describing motion whose acceleration is not constant, such as the motion of an object

con-nected to a spring or the motion of an object through a fluid.

EXPERIMENTS

Physics is a science based on experimental observations In view of this fact, we recommend

that you try to supplement the text by performing various types of “hands-on” experiments,

either at home or in the laboratory For example, the common Slinky™ toy is excellent for

studying traveling waves; a ball swinging on the end of a long string can be used to

investi-gate pendulum motion; various masses attached to the end of a vertical spring or rubber

band can be used to determine their elastic nature; an old pair of Polaroid sunglasses and

some discarded lenses and a magnifying glass are the components of various experiments in

optics; and the approximate measure of the free-fall acceleration can be determined simply

by measuring with a stopwatch the time it takes for a ball to drop from a known height The

list of such experiments is endless When physical models are not available, be imaginative

and try to develop models of your own.

PhysicsNow™ with Active Figures and Interactive Examples

We strongly encourage you to use the PhysicsNow™ Web-based learning system that

accompa-nies this textbook It is far easier to understand physics if you see it in action, and these new

materials will enable you to become a part of that action PhysicsNow™ media described in the

Preface are accessed at the URL http://physics.brookscole.com/ecp, and feature a three-step

learning process consisting of a Pre-Test, a personalized learning plan, and a Post-Test.

In addition to the Coached Problems identified with icons, PhysicsNow™ includes the

fol-lowing Active Figures and Interactive Examples:

Chapter 1 Active Figures 1.4 and 1.5

Chapter 2 Active Figures 2.2, 2.11, 2.12, and 2.13; Interactive Examples 2.5 and 2.8

Chapter 3 Active Figures 3.3, 3.13, and 3.14; Interactive Examples 3.3, 3.5, and 3.7

Chapter 4 Active Figures 4.6, 4.15, and 4.16; Interactive Example 4.7

Chapter 5 Active Figures 5.5, 5.15, 5.19, and 5.25; Interactive Example 5.5 and 5.8

Chapter 6 Active Figures 6.8, 6.11, and 6.13; Interactive Examples 6.3 and 6.6

Chapter 7 Active Figures 7.4, 7.13, 7.14, and 7.15; Interactive Example 7.5

Chapter 8 Active Figure 8.21; Interactive Examples 8.6 and 8.8

Chapter 9 Active Figures 9.3, 9.5, 9.6, 9.17, and 9.18; Interactive Examples 9.4 and 9.8

Chapter 10 Active Figures 10.10, 10.12, and 10.15

Chapter 12 Active Figures 12.1, 12.2, 12.8, 12.10, and 12.13

Chapter 13 Active Figures 13.1, 13.4, 13.7, 13.8, 13.10, 13.13, 13.18, 13.20, 13.23, 13.26, 13.28, and 13.29

Chapter 14 Active Figures 14.2, 14.8, 14.10, 14.15, and 14.21; Interactive Examples 14.1, 14.4, 14.5, and 14.6

Chapter 15 Active Figures 15.6, 15.11, 15.16, and 15.22; Interactive Example 15.1

Chapter 16 Active Figures 16.7, 16.11, 16.14, and 16.16; Interactive Examples 16.2 and 16.8

Chapter 17 Active Figures 17.4 and 17.10; Interactive Example 17.3

Chapter 18 Active Figures 18.1, 18.2, 18.5, 18.12, and 18.13; Interactive Examples 18.2 and 18.4

Chapter 19 Active Figures 19.2, 19.13, 19.15, 19.16, 19.17, 19.18, 19.19, and 19.24

Chapter 20 Active Figures 20.2, 20.4, 20.11, 20.15, 20.17, and 20.22

Chapter 21 Active Figures 21.1, 21.4, 21.6, 21.8, 21.12, and 21.19; Interactive Examples 21.4 and 21.6

Chapter 22 Active Figures 22.4, 22.6, 22.7, 22.16, and 22.22; Interactive Examples 22.1 and 22.4

Chapter 23 Active Figures 23.2, 23.12, 23.15, and 23.24; Interactive Examples 23.2, 23.6, and 23.8

Chapter 24 Active Figures 24.1, 24.16, 24.20, 24.21, and 24.26; Interactive Examples 24.1, 24.3, 24.6, and 24.7

Chapter 25 Active Figures 25.7 and 25.8

Chapter 26 Active Figures 26.4, 26.6, and 26.9

Chapter 27 Active Figures 27.2, 27.3, and 27.4; Interactive Examples 27.1 and 27.3

Chapter 28 Active Figures 28.7 and 28.17; Interactive Example 28.1

Chapter 29 Active Figures 29.1, 29.6, and 29.7; Interactive Example 29.2

Chapter 30 Active Figures 30.2 and 30.8

An Invitation to Physics

It is our hope that you too will find physics an exciting and enjoyable experience and that you will profit from this experience, regardless of your chosen profession Welcome to the exciting world of physics!

To see the World in a Grain of Sand And a Heaven in a Wild Flower, Hold infinity in the palm of your hand And Eternity in an hour.

William Blake, “Auguries of Innocence”

1.2 The Building Blocks

of Matter

1.3 Dimensional Analysis

1.4 Uncertainty inMeasurement andSignificant Figures

1.5 Conversion of Units

1.6 Estimates and Order-of-MagnitudeCalculations

1.7 Coordinate Systems

1.8 Trigonometry

1.9 Problem-Solving Strategy

The goal of physics is to provide an understanding of the physical world by developing

theo-ries based on experiments A physical theory is essentially a guess, usually expressed

mathe-matically, about how a given physical system works The theory makes certain predictions

about the physical system which can then be checked by observations and experiments If the

predictions turn out to correspond closely to what is actually observed, then the theory

stands, although it remains provisional No theory to date has given a complete description of

all physical phenomena, even within a given subdiscipline of physics Every theory is a work in

progress.

The basic laws of physics involve such physical quantities as force, velocity, volume, and

acceleration, all of which can be described in terms of more fundamental quantities In

me-chanics, the three most fundamental quantities are length (L), mass (M), and time (T); all

other physical quantities can be constructed from these three.

To communicate the result of a measurement of a certain physical quantity, a unit

for the quantity must be defined For example, if our fundamental unit of length is

defined to be 1.0 meter, and someone familiar with our system of measurement

re-ports that a wall is 2.0 meters high, we know that the height of the wall is twice the

fundamental unit of length Likewise, if our fundamental unit of mass is defined as

1.0 kilogram, and we are told that a person has a mass of 75 kilograms, then that

person has a mass 75 times as great as the fundamental unit of mass

In 1960, an international committee agreed on a standard system of units for

the fundamental quantities of science, called SI (Système International) Its units

of length, mass, and time are the meter, kilogram, and second, respectively

Length

In 1799, the legal standard of length in France became the meter, defined as one

ten-millionth of the distance from the equator to the North Pole Until 1960, the official

length of the meter was the distance between two lines on a specific bar of

platinum-iridium alloy stored under controlled conditions This standard was abandoned for

several reasons, the principal one being that measurements of the separation between

the lines are not precise enough In 1960, the meter was defined as 1 650 763.73

wave-lengths of orange-red light emitted from a krypton-86 lamp In October 1983, this

definition was abandoned also, and the meter was redefined as the distance traveled

by light in vacuum during a time interval of 1/299 792 458 second This latest

defini-tion establishes the speed of light at 299 792 458 meters per second

Mass

The SI unit of mass, the kilogram, is defined as the mass of a specific

platinum-iridium alloy cylinder kept at the International Bureau of Weights and Measures at

Sèvres, France As we’ll see in Chapter 4, mass is a quantity used to measure the

re-sistance to a change in the motion of an object It’s more difficult to cause a change

in the motion of an object with a large mass than an object with a small mass

Throughout the text, the PhysicsNow icon indi- cates an opportunity for you to test yourself on key concepts and to explore animations and interactions

on the PhysicsNow website at http:// physics.brookscole.com/ecp

Thousands of years ago, people in southern England built Stonehenge, which was used as a calendar The position of the sun and stars relative

to the stones determined seasons for planting or harvesting.

 Definition of the meter

the light emitted from the cesium-133 atom as its “reference clock.” The second is now defined as 9 192 631 700 times the period of oscillation of radiation from the cesium atom.

Approximate Values for Length, Mass, and Time Intervals

Approximate values of some lengths, masses, and time intervals are presented inTables 1.1, 1.2, and 1.3, respectively Note the wide ranges of values Study thesetables to get a feel for a kilogram of mass (this book has a mass of about 2 kilo-grams), a time interval of 1010seconds (one century is about 3 109seconds), or

TABLE 1.1

Approximate Values of Some Measured Lengths

Length (m)

Typical altitude of satellite orbiting Earth 2  10 5

Time required for light to travel across a proton 3  10 24

aA period is defined as the time required for one complete vibration.

Definition of the second 

1.2 The Building Blocks of Matter 3

two meters of length (the approximate height of a forward on a basketball team)

Appendix A reviews the notation for powers of 10, such as the expression of the

number 50 000 in the form 5 104

Systems of units commonly used in physics are the Système International, in

which the units of length, mass, and time are the meter (m), kilogram (kg), and

sec-ond (s); the cgs, or Gaussian, system, in which the units of length, mass, and time

are the centimeter (cm), gram (g), and second; and the U.S customary system, in

which the units of length, mass, and time are the foot (ft), slug, and second SI units

are almost universally accepted in science and industry, and will be used throughout

the book Limited use will be made of Gaussian and U.S customary units

Some of the most frequently used “metric” (SI and cgs) prefixes representing

powers of 10 and their abbreviations are listed in Table 1.4 For example, 103m is

equivalent to 1 millimeter (mm), and 103m is 1 kilometer (km) Likewise, 1 kg is

equal to 103g, and 1 megavolt (MV) is 106volts (V)

A 1-kg ( 2-lb) cube of solid gold has a length of about 3.73 cm ( 1.5 in.) on

a side If the cube is cut in half, the two resulting pieces retain their chemical

identity as solid gold But what happens if the pieces of the cube are cut again and

again, indefinitely? The Greek philosophers Leucippus and Democritus couldn’t

accept the idea that such cutting could go on forever They speculated that the

process ultimately would end when it produced a particle that could no longer be

cut In Greek, atomos means “not sliceable.” From this term comes our English

word atom, once believed to be the smallest particle of matter, but since found to

be a composite of more elementary particles

The atom can be naively visualized as a miniature Solar System, with a dense,

positively charged nucleus occupying the position of the Sun, with negatively

charged electrons orbiting like planets

Two basic entities — protons and neutrons — occupy the nucleus The proton is

nature’s fundamental carrier of positive charge, equal in magnitude but opposite

in sign to the charge on the electron The number of protons in a nucleus

deter-mines what the element is For instance, a nucleus containing only one proton is the

nucleus of an atom of hydrogen, regardless of how many neutrons may be present

Extra neutrons correspond to different isotopes of hydrogen — deuterium and

tri-tium — which react chemically in exactly the same way as hydrogen, but are more

massive An atom having two protons in its nucleus, similarly, is always helium,

al-though again, differing numbers of neutrons are possible

A neutron has no charge and has a mass about equal to that of a proton One of

its primary purposes is to act as a “glue” to hold the nucleus together If neutrons

were not present, the repulsive electrical force between the positively charged

pro-tons would cause the nucleus to fly apart

The division doesn’t stop here; it turns out that protons, neutrons, and a zoo of

other exotic particles are now thought to be composed of six particles called

quarks(rhymes with “forks,” though some rhyme it with “sharks”) These particles

have been given the names up, down, strange, charm, bottom, and top The up, charm,

and top quarks each carry a charge equal to  that of the proton, whereas the

down, strange, and bottom quarks each carry a charge equal to  the proton

charge The proton consists of two up quarks and one down quark (see Fig 1.1),

giving the correct charge for the proton,  1 The neutron is composed of two

down quarks and one up quark and has a net charge of zero

The up and down quarks are sufficient to describe all normal matter, so the

ex-istence of the other four quarks, indirectly observed in high-energy experiments,

is something of a mystery It’s also possible that quarks themselves have internal

structure Many physicists believe that the most fundamental particles may be tiny

loops of vibrating string

1 3

2 3

TABLE 1.4

Some Prefixes for Powers

of Ten Used with “Metric” (SI and cgs) Units

Power Prefix Abbreviation

1.3 DIMENSIONAL ANALYSIS

In physics, the word dimension denotes the physical nature of a quantity The

dis-tance between two points, for example, can be measured in feet, meters, or

fur-longs, which are different ways of expressing the dimension of length.

The symbols that we use in this section to specify the dimensions of length, mass,and time are L, M, and T, respectively Brackets [ ] will often be used to denote thedimensions of a physical quantity For example, in this notation the dimensions of

velocity v are written [v]  L/T, and the dimensions of area A are [A]  L2 Thedimensions of area, volume, velocity, and acceleration are listed in Table 1.5, alongwith their units in the three common systems The dimensions of other quantities,such as force and energy, will be described later as they are introduced

In physics, it’s often necessary either to derive a mathematical expression or

equation or to check its correctness A useful procedure for doing this is called mensional analysis , which makes use of the fact that dimensions can be treated as algebraic quantities Such quantities can be added or subtracted only if they havethe same dimensions It follows that the terms on the opposite sides of an equationmust have the same dimensions If they don’t, the equation is wrong If they do,the equation is probably correct, except for a possible constant factor

di-To illustrate this procedure, suppose we wish to derive a formula for the distance

x traveled by a car in a time t if the car starts from rest and moves with constant celeration a The quantity x has the dimension length: [x]  L Time t, of course, has dimension [t]  T Acceleration is the change in velocity v with time Since v has dimensions of length per unit time, or [v] L/T, acceleration must have dimen-

ac-sions [a] L/T2 We organize this information in the form of an equation:

Looking at the left- and right-hand sides of this equation, we might now guess that

This is not quite correct, however, because there’s a constant of proportionality —

a simple numerical factor — that can’t be determined solely through dimensional

Quark composition of a proton u

d

Gold cube

Gold

nucleus Proton

Neutron u

Figure 1.1 Levels of organization

in matter Ordinary matter consists of

atoms, and at the center of each atom

is a compact nucleus consisting of

protons and neutrons Protons and

neutrons are composed of quarks.

The quark composition of a proton is

shown.

TABLE 1.5

Dimensions and Some Units of Area, Volume, Velocity, and Acceleration

System Area (L 2 ) Volume (L 3 ) Velocity (L/T) Acceleration (L/T 2 )

1.4 Uncertainty in Measurement and Significant Figures 5

analysis As will be seen in Chapter 2, it turns out that the correction expression is

When we work algebraically with physical quantities, dimensional analysis allows

us to check for errors in calculation, which often show up as discrepancies in units

If, for example, the left-hand side of an equation is in meters and the right-hand

side is in meters per second, we know immediately that we’ve made an error

x1

2at2

Goal Check an equation using dimensional analysis

Problem Show that the expression v  v0 at, is dimensionally correct, where v and v0 represent velocities, a is acceleration, and t is a time interval.

Strategy Analyze each term, finding its dimensions, and then check to see if all the terms agree with each other

AND SIGNIFICANT FIGURES

Physics is a science in which mathematical laws are tested by experiment No

physi-cal quantity can be determined with complete accuracy because our senses are

physically limited, even when extended with microscopes, cyclotrons, and other

gadgets

Knowing the experimental uncertainties in any measurement is very important

Without this information, little can be said about the final measurement Using a

crude scale, for example, we might find that a gold nugget has a mass of 3

kilo-grams A prospective client interested in purchasing the nugget would naturally

want to know about the accuracy of the measurement, to ensure paying a fair

price He wouldn’t be happy to find that the measurement was good only to within

a kilogram, because he might pay for three kilograms and get only two Of course,

he might get four kilograms for the price of three, but most people would be

hesi-tant to gamble that an error would turn out in their favor

Accuracy of measurement depends on the sensitivity of the apparatus, the skill

of the person carrying out the measurement, and the number of times the

mea-surement is repeated There are many ways of handling uncertainties, and here

we’ll develop a basic and reliable method of keeping track of them in the

measure-ment itself and in subsequent calculations

Suppose that in a laboratory experiment we measure the area of a rectangular

plate with a meter stick Let’s assume that the accuracy to which we can measure a

particular dimension of the plate is 0.1 cm If the length of the plate is

mea-sured to be 16.3 cm, we can claim only that it lies somewhere between 16.2 cm

and 16.4 cm In this case, we say that the measured value has three significant