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The Career Encounters: Mechanical Engineering videotape.. e A synopsis of the Career Encounters: Mechanical Engineering videotape that you should photocopy and distribute to your student

“Tools of Discovery’’

Table of Contents

For The Teacher:

An Engineering View of Civilization and Science (for all classes) 1

Using Tools of Discovery in Your Classroom (for all teachers) 2

Synopsis of the Career Encounters Videotape (all classes) 3

A Matrix of Teaching Concepts (for all teachers) 4

Guide to Thinking Like An Engineer (for all classes) .::::::.:: ‘5

Guide to Water And Wheels Activity (for Earth Science classes) i

Guide to Biomechanics Activity (for Biology classes) 9

Guide to Compression Activity (for Chemistry & Physical Science classes) 11

Guide to Leverage Activity (for Physics & Physical Science classes) 13

Guide to Helping Students Identify Working Styles (for all classes) 15

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An Engineering View

Of Civilization And Science

e are the inventors and the toolmakers No other

species creates and uses tools the way we do A

chimpanzee can use a twig

to pry open an anthill, there

is a species of seabird that cracks oysters open on a rock, and troops of baboons have even been known

to use sticks and stones as weapons But no chimp,

bird or baboon — or any other animal — has yet

conceived of a tool that combines both stick and

stone That is invention, and that is the sole province

of humankind

Probably we invent tools because we are so poorly

equipped to survive otherwise Without feathers or

fur, or claw or fang, we are hopelessly disadvantaged

in the fight for survival Except that we have

perception, imagination, the ability to plan ahead

Almost every attribute that defines us as humans is

applied to making and using tools and systems that

give us the definitive advantage in the fight to survive

We can use our tools to outreach and outmaneuver

our natural enemies — and to outwit nature itself

It all starts with a stick and a stone Place a stick

across a stone and you have invented the simplest

of machines, a lever With that lever you can vastly

increase the efficiency of your labor You have

enhanced nature by employing a “mechanical

advantage” far beyond your physical capabilities The

word “mechanical” itself suggests deception: it comes

from a Greek word that means “I contrive a

deception.”

What powerful deceptions these machines are

Almost everything about our physical world today

is influenced - for better or worse — by the machines

we have engineered Sticks and stones gave way to

iron and steam, which gave way to electricity and

plastic Soon, we will be crafting microscopic

machines spanning no more than one or two

molecules, and composed entirely of biological

components

The beauty of every machine is not its composition,

or even its mechanical capability It is the process

of thinking that led to its creation And that process

is engineering — the process of solving problems under constraints Engineers look for practical solutions to specific problems By contrast, scientists seek knowledge without regard to using that knowledge to solve a specific problem

Engineering as a discipline distinct from science is

a relatively recent innovation Early scientists made the tools they used — Galileo with his telescope is

a prime example Early engineers were discovering new scientific concepts ~ Leonardo da Vinci formulated the law of the lever from his development

of catapults The first engineer we know by name and achievement is Imhotep, who built the stepped pyramid in Egypt about 4,500 years ago There is

no record of Imhotep developing any new theories

of physics or mathematics, but we do know that he applied these disciplines to solve the problems of building a structure that still stands today

Engineering, then, is the profession of applying science and mathematics to the solution of practical problems Inevitably, solving problems makes things better — and a belief in the value and possibility of progress is the fundamental rationale for human civilization A necessary part of being human is our ability to imagine a future that is better than the present As practical problem-solvers, the women and men who are engineers are in the business of improving quality of human life

Change always brings more change The machines

we engineer depend upon scientific achievements, and in turn, new scientific understanding is gained

by using these machines For example, space travel was possible only after thousands of scientific discoveries Now satellites are opening up entirely

new areas of scientific research

And so our species moves forward, machine by machine Today, engineers are the toolmakers — the

makers of the Tools of Discovery

Using ‘‘Tools Of Discovery’’

In Your Classroom

he Tools of Discovery program — which includes

this booklet and the Career

Encounters videotape presents an engineering view

of the physical sciences

It supplements your curriculum by showing your students how scientific concepts are applied in the

“real world”

Inaddition, Tools of Discovery helps your students

to start thinking about a career, and the personal

factors that go into that decision It also offers your

students a look at the career opportunities in the

field of mechanical engineering and provides

information on the high school and college

preparation necessary for an engineering career

This program was developed by the American

Society of Mechanical Engineers, with the

cooperation of experienced high school classroom

teachers and engineering educators

The student activities included in Tools of Discovery

are targeted to earth science, biology, chemistry and

physics They are also appropriate for general science

classes These activities let students explore the uses

of simple machines in technology related to each

science discipline

Tools of Discovery includes:

1 The Career Encounters: Mechanical Engineering

videotape It introduces students to mechanical

engineers, who discuss their work The videotape

includes a “working style’ chart that shows

students that career choices involve not only what

they would like to do, but how they like to do it

2 This booklet includes all of the student activity

photocopy masters and suggested lesson plans for

the program Included are:

¢ A brief overview of the impact of engineering

on science and civilization You will want to

photocopy it and distribute it to your students

(Page 1.)

e A synopsis of the Career Encounters:

Mechanical Engineering videotape that you should photocopy and distribute to your students (Page 3.)

e A matrix of teaching concepts that identifies the subject matter of each student activity

(Page 4.)

© Teacher's guides for each student activity

(Pages 5, 7, 9, 11, 13 and 15.)

© A student activity that introduces the

engineering process in a problem-solving exercise (Page 6.)

¢ Four student activities, one each related to

earth science, biology, chemistry and physics

(Pages 8, 10, 12 and 14.)

¢ A student activity that introduces “working

style” as a consideration in choosing a career

(Page 16.)

© Six career background photocopy masters that provide practical information on mechanical engineering work, job opportunities, educational requirements and career information resources (Pages 17 through 22.)

SUGGESTED PROGRAM USE PLAN

Distribute “Engineering View.”

View and discuss the videotape

Distribute the videotape synopsis

Use the “Working Styles” questionnaire

Use the “Thinking Like an Engineer”

Synopsis of the

‘“‘Career Encounters’”’ Videotape

Encounters: Mechanical Engineering introduces high school — students to

mechanical engineering It runs approximately 13

minutes and shows a variety

of mechanical engineers explaining what they do and why they find satisfaction

in their work

The video also features a “working style” chart that

shows students that career choices involve not only

what they would like to do, but how they like to do

it The chart divides working styles into four groups 5

The mechanical engineers featured in the video work

in the computer, automotive, biotechnology research,

manufacturing, product marketing, power generation

and petrochemical refining industries These fields

represent only a portion of the diversity of

mechanical engineering fields The key points in the 6

video are:

1 Behind every mechanical process are the people

who must first envision it, and then make it

happen These are the mechanical engineers

They use the physics of motion and power to solve

he videotape Career 4 To know your career, you need to know yourself

— not only what you like to do, but how you like

to do it The video presents a “work style” chart that divides working styles into fast-paced or methodical, with a focus on people or tasks (Therể is no value judgment about working styles.) Those who like fast-paced work with people are communicators They who like fast-paced work

with tasks are directors Those who like more

methodical work with people are integrators

Those who like more methodical work with tasks

are thinkers Mechanical engineers are found in all four groups

Mechanical engineering offers a great deal of

opportunity in both work style and work place Almost every industry employs mechanical engineers, and many with mechanical engineering training work in sales, marketing, administration, research and product design

One mechanical engineer notes that engineering training provides a rational, structured thought process for solving problems — and that process forms a good basis for many types of

management

manufacturing problems, design new products

and create technologies that expand human

potential

2 Engineers solve problems They use their

knowledge of mathematics and science to

transform their ideas into a reality that is useful

Mechanical engineering requires persistence and

creativity, and learning to think in terms of systems

and structures, materials and use, power and

control

3 People who succeed in engineering usually have

a curiosity about how things work, and why they

SOME THINGS TO THINK ABOUT

© Scientists focus on seeking knowlege, regardless of its practical use Engineers focus on solving practical problems

How are these two careers compatible?

¢ Engineers use many tools in their work The video shows several How do you think computers have changed engineering?

work the way they do These people also have a

desire to make things work better Engineers need

a strong background in mathematics and science,

and the ability to communicate their ideas in

writing.

Biology

Biomechanics

Chemistry Compression

Physics Leverage

Engineering is the practical

application of science and

mathematics concepts

Engineers work under constraints

to develop practical solutions to

concerned with materials design

and the selection of materials for

specific tasks

al

Cooperative learning; students

working as design teams

Waterpower and the Wheel-and-

Axle as an industrial force

Biomechanics and biotechnology

Compression and combustion in

automobiles; Boyle’s Law and

Charles’ Law of gases

Classes of levers; Archimedes’ law

of levers, compound levers

ngineering is a distinct way

of thinking about the physical world It involves a step-by-step problem-solving

routine that nonetheless

leaves plenty of room for personal creativity

Science has the objective of increased knowledge, regardless of its practical use

Engineering focuses on practical solutions to specific

problems

SUMMARY: This activity examines the engineering

process, and lets students use the process to arrive

at a design solution to a mechanical problem

GOAL: At the conclusion of this activity, your

students should be able to identify and describe the

nine steps of the engineering design process They

should also be able to show how they applied each

step to the task of designing a solution to a specific

mechanical engineering problem

ORGANIZATION: This activity can be completed

individually, but you will probably want to have your

students work in design teams to more closely

simulate the real world of engineering Note: You

can repeat this activity by assigning different

engineering challenges and reconfiguring design

teams each time

TIME REQUIRED: Two class periods

SUGGESTED LESSON PLAN:

1 Organize your class into groups of five or six

students each Distribute the “Thinking Like an

Engineer” student activity sheet Review and

discuss the nine engineering process steps listed

on the student activity sheet | Ĩ

2 Assign an engineering design challenge from the

“Engineering Challenges” list on this page

Assigning the same challenge to each team allows

for competition; assigning a different challenge

to each team allows for a diverse set of engineering

8 Let each team use at least one class period to

brainstorm a solution and assign team members the various design and communications tasks

In the second class period have each team

communicate its solution to the class Evaluate

primarily for adherence to the design steps and responsiveness to the problem Secondary

evaluation criteria include completeness of the

presentation, creativity of the solution, and optimum use of resources

Using the criteria in step 4, have the class vote

on the best design solution presented

Enrichment: Have your student teams make the products they design

¢ A machine that can very quickly chill

an aluminum can of soda

¢ A device that will make it easy to parallel park a car

© A device for providing cool air to bicycle riders

© A better way to automatically peel

a grape

© A way people in wheelchairs can easily

use a standard shower

e A more effective car windshield wiper

e An automatic dog-food dispenser

and you have to be as specific as possible

Here's what you have to consider:

1 Identify the need This is easy; your teacher has

already established the need for a solution

2 Define the problem This is difficult Be sure you

are addressing the real cause of the problem

3 Search for information For this exercise, much

will come from your own experience In the real

world, engineers often research technical literature

to see how other engineers have addressed the

problem and conduct market surveys to determine

whether the public will accept the proposed

solution

4 Set design criteria and constraints In the real

world, cost is usually the biggest constraint But

for this exercise assume an unlimited budget List

the criteria that will determine the success of your

design

5 Consider a number of solutions Often developing two ideas lets you compare the benefits of each and

ngineers solve problems The way they solve problems is probably the distinguishing feature

This unique engineering process was illustrated in the beginning of the videotape Career

Encounters: Mechanical Engineering The automotive engineer briefly described the way

a team of mechanical engineers redesigned the under-the-hood air flow of a sports car

The engineering design process they followed is described in the box on this page

Your task is to follow the step-by-step engineering design process to solve the specific problem your teacher assigns Your solution has to include how you address each step,

ENGINEERING DESIGN PROCESS

1 Identify a need

2 Define the problem

3 Search for information

4 Set your criteria and constraints

5 Consider a number of solutions

6 Analyze your design

7 Make a decision

8 Develop specifications of your design

9 Communicate your design solution

put together a final design that includes the best of both

6 Analyze your design If you're working as a team, let each team member come up with one potential problem

with the design Then rework your idea to eliminate as many of the problems as possible

7 Decision Make your final changes

8 Specifications Engineers usually create detailed mechanical drawings and a list of materials for their design

solutions You just have to produce a sketch of your design and write up a description of it

9 Communicate Present your final design solutions to the class Your presentation should include a step-by-

step description of how you addressed each design step, your design sketch and written description

Good luck

been around for at least 1,000 years by that time)

into the first water mill He attached paddles to the

wheel and lowered it into a fast-flowing stream Then

he attached his grain grindstone to the wheel's axle

The water turned the wheel, the wheel turned the

axle and the axle turned the grinding stone This

basic idea -— with a few improvements —is still in use

today Only now, water power drives giant turbines

that each produce enough electric power (without

polluting the air or water) to serve 60,000 homes

SUMMARY: This activity introduces the mechanics

of hydro-energy It shows how humans have used

water to turn wheels, and how a wheel-and-axle

transfers energy from one direction to another

GOAL: At the conclusion of this activity, your

students should be able to describe how falling water

can be used to produce work, and how humans use

water as a source of energy The students should also

be able to identify the key parts of a water mill and

hydroelectric turbine, and describe how a wheel-and-

axle transfers energy from one direction to another

ORGANIZATION: This activity can be completed

individually, but you might want your students to

work in design teams to more closely simulate the

real world of engineering

TIME REQUIRED: One class period

SUGGESTED LESSON PLAN:

1 Organize your class into groups of three or four

students each Distribute the “Water & Wheels”

student activity sheet

Review the water mill design graphic on the student activity sheet Discuss the importance of

grain-grinding to make bread Students who cook should be able to contribute to the discussion

Have students describe the operation of the water

mill illustrated Discuss other uses for a water-

driven wheel-and-axle (generating electricity)

Now focus on the wheel-and-axle illustration Show how the wheel-and-axle is a lever (The axle hub is the fulcrum, the water is the effort, the force

the millstone exerts on the axle is the resistance, and the axle’s radius is the resistance arm.) Have students trace the flow of energy in this diagram

Point out that not all wheel-and-axle assemblies are the same In the water mill, the effort is transmitted from the wheel to the axle But in

a car the effort is transmitted from the axle to the wheel

Have students describe why water is a good prime mover (supplier of effort) Ask students why falling water is not used for all power generation (Advantages of water; it is less expensive, renewable and non-polluting The key disadvantage is availability; most of the appropriate locations are already being used.) Have students identify and describe other simple

devices that employ the same “wheel-and-axle”

principles (Usual ones include a car’s steering wheel and the wheel of a boat Unusual examples

include a screwdriver, a water faucet and a key in

a keyhole.) Introduce the concept of mechanical advantage

and show how the ration of the size of the wheel

to its axle determines the magnification of force (mechanical advantage) For example, a 10” wheel

ona 1” axle magnifies force by 10

As an enrichment activity, have students research and illustrate the operations of a hydroelectric plant, especially the wheel-and-axle assembly in

a turbine

STUDENT ACTIVITY

COPYMASTER

‘“‘Water And Wheels’’

ater is one of the most powerful natural forces on the planet The wheel is one of the earliest machines invented by humans Together, water and wheels have changed the face of the planet and the way we live on it

The earliest partnership of water and wheels was formed in what is now Iraq, and the purpose was to grind grain with less human effort There the inventor attached paddles

to a wheel and lowered it into a fast-moving stream An axle connected the wheel to a grind stone The water turned the wheel, the wheel turned the axle, and the axle turned

Describe how the water mill works What is the

Besides grinding, what other uses are made of

What are the advantages of using water as a source

What is the practical problem this design solves?

What other solutions might be used to achieve the

same result? What are the advantages and

disadvantages of this “water mill” compared to the —“UNDERSHOT” WHEEL

other solutions?

GRINDING

STONE

energy source? What is the importance of the axle?

What type of work does it do?

water-powered wheels?

of energy? What are its disadvantages?

What other machines or systems use a similar xe

wheel and axle design?

In the early 1800s, the Industrial Revolution first The inventor of the first water mills can be described as a

took place in America in New England Why? mechanicalengineer The design uses principles of mathematics

~ A modern water mill would be designed by a 4nd science to solve a practical problem involving motion

mechanical engineer What factors would she have

to consider to make her design effective?

Now consider the diagram below How does this diagram show that a wheel-and-axle is like a lever? Trace

the input of energy and the output of work in this machine This machine is designed to produce a “mechanical

advantage.’ What do you think that term means?

9 The wheel shown here is 10” in diameter, and the

axle is 1” in diameter Can you calculate the

AXLE “mechanical advantage” of this machine? What

would be the mechanical advantage if the wheel is 15” and the axle is 3”?

WHEEL

iomechanics is the branch of

science that brings together

two branches of knowledge

that may seem to be quite different - biology and mechanical engineering

Biomechanics takes the

understanding of machines and motion that engineers have developed, and

applies it to explain how living things move and work

One branch of biomechanics focuses on the marriage

of mechanical engineering and medicine in the

design of artificial systems that replace human joints

and limbs Another branch, called ergonomics,

focuses on designing machines that are more

compatible to the way humans move

SUMMARY: This activity examines the similarities

- and differences — between animal motion and

mechanical motion

GOAL: At the conclusion of this activity, students

should be able to discuss the similarities and

differences between animal motion and mechanical

motion in terms of energy inputs, work

accomplished, and system designs They should also

be able to identify the application of simple machine

concepts in various biological designs

ORGANIZATION: This activity can be completed

individually, but you will probably want to have your

students work in design teams to more closely

simulate the real world of engineering

TIME REQUIRED: One class period to complete

the activity sheet; several periods to research and

complete the research assignment, if given

SUGGESTED LESSON PLAN:

1 Organize your class into groups of three or four

students each Distribute the “Biomechanics”

student activity sheet, Note: The sheet contains

a section of questions and a research assignment

You do not have to assign the research if time

3 Discuss the fact that the same laws of physics apply

to all motion, whether animate or inanimate The

movement of any body requires energy

4, Discuss the sources of energy for biological motion and mechanical motion (Biological: food;

Mechanical: fuel) Review plant photosynthesis

and digestion Discuss the carbon cycle Have students trace the energy flow in plants and animals Then have the students compare and contrast the biological energy flow to the energy

flow in an automobile (Note: the basic source of energy for plants, animals and cars is the sun.)

5 Refer to the illustrations and questions on the student activity sheet Students are asked to identify the similarities and differences between

biological and mechanical systems Make sure

they understand that the similarities do not have

to be exact

6 Review the answers to the questions, making sure students are able to discuss each system's

similarities and differences

7 The optional research activity lets students find

out more details of how different mechanical

systems are designed after biological ones Their reports can be either written or oral All reports

should also include a sketch or diagram that shows the systems’ similarities and differences, as

well as their basic designs

An excellent resource on biomechanics is:

Exploring Biomechanics: Animal Motion,

by R McNeill Alexander (Scientific American Press, 1992)

STUDENT ACTIVITY

COPYMASTER

*“‘Biomechanics’’

erhaps humans always have been envious of the grace, speed and agility of certain animals

Our intelligence gave us the ability to survive in the animal world, but it has only been recently that we have been able to duplicate many of the physical feats of animals Now airplanes carry us past eagles, and submarines dive deeper than whales Our cars can outrun cheetahs, and our bulldozers out-pull elephants Ironically, the basic design ideas

of many of the machines we use to outperform animals come from the animals themselves

For example, airplanes use the same laws of aerodynamics that keep birds aloft, and the

ballast principle employed by submarines is not much different than that used by whales

Biomechanics deal with the motion of living things It applies the understanding of machines and materials

that engineers have developed to explain how living things move and work

1 Below is a set of sketches of system designs Some are of biological systems, and some are of mechanical

systems Your task is to identify a similar system for each, pairing a biological with a mechanical

2 For each “design pair” you have identified, describe how the systems receive energy and perform work Identify

the source(s) of energy for each system and the work it performs Show similarities and differences

3 Assume that you are a mechanical engineer working on the design of an artificial knee for injured football

players Where are some of the design considerations you will have to take into account? What capabilities

will you want to design into the knee? What capabilities of the human knee might you be willing to give up

in your design? Is cost a major consideration in your design? Why, or why not?

4 Study your own elbow and

forearm Make a model of this

system using materials from home

or school This system resembles

a type of simple machine Identify

that machine and describe how the

two systems (your elbow and

forearm, and the machine) are

similar Describe how each system

converts energy and performs

work Describe the mechanical

advantage each system produces

5 Select any one of the following

mechanical systems and research

the early days of its design to see

how it mimicked one or more

natural systems: Submarine,

Telephone, Helicopter, Airplane,

Jet Engine

Report your findings Your report can

be written or oral, but must include

a sketch or diagram that compares

the mechanical and natural system

10