This is the first of a weekly set of web pages that sumarize the material of the course. Material appearing on these pages is likely to appear in the weekly quizzes. You are responsible for commiting the material on these pages to memory.
We shall work with the following physical quantites in terms of these units.
Quantity 
Unit 
Dimensions 
Meaning 
Mass 
kilogrammes (kg) 
kg 
amount of material 
Length 
metres (m) 
m 

Time 
seconds (s) 
s 

Temperature 
Kelvin (K) 
1K = 1°Celsius 

Velocity 
metres per second 
m s^{1} 
how fast something goes 
Acceleration 
metres per second squared 
m s^{2} 
how fast velocity alters 
Force 
Newtons (N) 
1N = 1 kg m s^{2} 
a push or pull, what it takes to make something
accelerate 
Work 
Joules (J) 
1J = 1 kg m^{2} s^{2} 
force times distance, when you do physical work you get
tired 
Energy 
Joules (J) 
1J = 1 kg m^{2} s^{2} 
Energy is a measure of the ability to do work. 
Pressure 
Pascals (Pa) 
1 Pa = 1 N m^{2} 
Force per unit area. Used to describe forces that are
applied over some large area. Force = Pressure × Area 
Remember that distance, velocity, acceleration, and force are all quantities that have both a size and direction associated with them. We call quantities with both a size and a direction VECTOR quantities.
The other quantities, mass, time, temperature, work, energy, and pressure all have only a size. Quantities that have only a size are called SCALAR quantities.
We shall find it useful to use Scientific Notation to write out numbers. The significant digits will be written starting in the tens or units place and with as many decimal places as are waranted by the precision of the number. The actual magnitude will then be added by showing a power of ten multiplier. For example
125,536 = 1.2536×10^{5}, 100,000,000 = 10^{8}, 0.013 = 1.3×10^{2}, 0.000001156 = 1.1156×10^{6}.
We often simplify our use of scientific notation by the use of power names. Thus we say 1000m = 1kilometre and 0.001m = 1millimetre. Here are the common prefixes in use
Prefix 
Symbol 
Power 
Example 
mega 
M 
10^{6} 
1,000,000 Joules = 1 mega Joule = 1 MJ 
kilo 
k 
10^{3} 
1,000 metres = 1 kilometer = 1 km 
milli 
m 
10^{3} 
0.001 grammes = 1 milligramme = 1mg 
micro 
µ 
10^{6} 
0.000001 Newtons = 1 micro Newton = 1µN 
NOTE. No matter what Christopher Loyd ("Doc" in Back to the Future) thinks, giga is pronounced geega not djiga!
Periodic motion is any motion that repeats itself after a time
called the Period. symbol P or τ.
We define the Frequency of motion by f = 1/τ so that τ = 1
/f.
We measure the frequency in Hz. 1 Hz = 1 repeat per second.
An oscillating system (and this includes a system that is
to transmit a wave) must have
1) a massa source of inertia.
When the mass moves it carries energy in the form of Kinetic
Energy.
2) a restoring forcea force like a spring that pulls back when
pushed and pushes back when pulled.
When the "spring" is compressed or expanded it stores energy in the
form of Potential Energy.
A simple oscillator moves in a way that we call Sinusoidal
Motion.
A graph of the position of the mass versus time looks like this
NOTE. We also sometimes use the term Simple Harmonic Motion.
These merit inclusion but are not required to be memorized.
These are prefixes that you may meet but that are less common. You should be aware of them and know where to look them up but you don't have to have them memorized.
Prefix 
Symbol 
Power 
Example 
tera 
T 
10^{12} 
1,000,000,000,000 Watts = 1 Terawatt = 1 TW 
giga 
G 
10^{9} 
1,000,000,000 Pascals = 1 giga Pascal = 1 GPa 
centi 
c 
10^{2} 
0.01 metres = 1 centimetre = 1cm 
nano 
n 
10^{9} 
0.000000001 Joules = 1 nano Joule = 1nJ 
pico 
p 
10^{12} 
0.000000000001 m = 1 pico meter= 1 pm 
We often use a scaled version of frequency becuase it fits the math better. The angular frequency has symbol ω, the Greek letter omega. We have ω=2πf.