00 intro to physics

Introduction Click to continueIntro to Mechanics is the port of entry into physics.. NOTE Symbols and units Symbols are letters used in formulas.. Units are letters used in quantities..

Introduction Click to continue

Intro to

Mechanics is the port of entry into physics A job well done

in mechanics will form a solid foundation for the rest of the

subject

NOTE

Symbols and units

Symbols are letters used in formulas.

Units are letters used in quantities.

Do not confuse symbols with units.

CAUTION

m represents mass

t represents time

F represents force

v represents velocity

W represents work etc etc.

Here are some example

s

kg kilograms for mass

s seconds for time

N newtons for force

m/s meters/second for velocity

J joules for work

m meters for length etc etc.

Here are some example

s

Look! Some

units use

capital letters

a m

F =

t

v

x Sin g

a=

20 kg 22.5 s

400 N -200 J

Note that you will need to memorize the units because they are standard and cannot be changed and they are mandated by law

Mass Time Force Energy

It is the unit that identifies what the quantiy represents

2 i

2

f v v

a

d

Note that we can change symbols at any time and use whatever symbols we like

For example

Introduction Click to next slide Click to continue

BASIC QUANTITIES

There are three basic quantities in mechanics.

Length Mass Time

UNIT meter kilogram second

All other quantities in mechanics are derived from these basic three and are

known as “derived” quantities.

NOTE

Remember:

Only these units are allowed

in physics formulasresponsibility to co! It is your

nvert all quantities into basic units!

F

F

Hypotenuse is double

opposite side

While the value for g is 9.8 m/s2, for quick practice, you may use 10 m/s2 to simplify your calculations

While the value for g is 9.8 m/s2, for quick practice, you may use 10 m/s2 to simplify your calculations

From a past physics exam

NOTE

… and good luck!