This document introduces some basic concepts in mechanics including symbols, units, and quantities. It discusses that symbols represent formulas, units represent quantities, and units are standardized while symbols can be changed. The three basic quantities in mechanics are identified as length, mass, and time, with their standard units being meters, kilograms, and seconds. Other quantities are derived from these three basic quantities. Formulas are also discussed.

3. 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.
Symbols and units
Symbols are letters used in formulas.
Units are letters used in quantities.
Do not confuse symbols with units.
m represents mass
t represents time
F represents force
v represents velocity
W represents work
etc. etc.
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.
a
m
F
t
v
a


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
2 

s
d
Note that we can change symbols at any
time and use whatever symbols we like.

4. Introduction 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.

5. Formulas

6. Formulas

7. Formulas
Hypotenuse is double
opposite side

8. 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

9. … and good luck!