# Intro to Physics ```Symbols and units
Intro
Symbols areto
letters used in formulas.
Units are letters used in
quantities.
Note
that we can change symbols at any
Mechanics is the port of entrytime
into
physics.
A job
well done
and
use whatever
symbols
we like.
in mechanics will form a solid foundation
for the rest of the
m represents mass Note that you will need to memorize
subject.
because
they are standard
Do not confuse
symbols
with
units.
t represents
time the units
F represents force and cannot be changed and they
is the unit
that identifies
kg kilograms
for mass
areItmandated
by law.
v represents
velocity
F

m
a
d
what
the
quantiy
represents.
s
seconds
for
time
W represents work
N
newtons for force
2
2
etc. etc.
2
a

v

v
s
f
i
m/s meters/second for velocity 20 kg
Mass
J
joules for work
22.5
 vs
Time
a 
m
meters for length
Force
400 tN
a
 g Sin x
etc. etc.
-200 J
Energy
Introduction
Click to continue
BASIC QUANTITIES
Length
UNIT
meter
Mass
kilogram
There are three basic quantities in mechanics.
Time
second
All other quantities in mechanics are
derived from these basic three and are
known as “derived” quantities.
Introduction
Click to continue
Formulas
Formulas
Formulas
Hypotenuse is double
opposite side
From a past physics exam
While the value for g is 9.8 m/s2, for quick practice,
you may use 10 m/s2 to simplify your calculations.
… and good luck!
```