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 velocity = distance travelled 
Acceleration 
metres per second squared 
m s^{2} 
how fast velocity alters acceleration = change in velocity 
Force 
Newtons (N) 
1N = 1 kg m s^{2} 
a push or pull, what it takes to make something accelerate acceleration = total applied force 
Work 
Joules (J) 
1J = 1 kg m^{2} s^{2} 
force times distance, when you do physical work you get tired Work=Force × Distance moved in direction of force. 
Energy 
Joules (J) 
1J = 1 kg m^{2} s^{2} 
Energy is a measure of the ability to do work. Work done = Energy after  Energy before 
Pressure 
Pascals (Pa) 
1 Pa = 1 N m^{2} 
Force per unit area. Used to describe forces that are applied over some large area. Pressure = Total
Force 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 
giga 
G 
10^{9} 
1,000,000,000 Pascals = 1 giga Pascal = 1 GPa 
mega 
M 
10^{6} 
1,000,000 Joules = 1 mega Joule = 1 MJ 
kilo 
k 
10^{3} 
1,000 metres = 1 kilometer = 1 km 
centi 
c 
10^{2} 
0.01 metres = 1 centimetre = 1cm 
milli 
m 
10^{3} 
0.001 grammes = 1 milligramme = 1mg 
micro 
µ 
10^{6} 
0.000001 Newtons = 1 micro Newton = 1µN 
nano 
n 
10^{9} 
0.000000001 Joules = 1 nano Joule = 1nJ 
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
= P, called the Period.
We define the Frequency of motion by f = 1/P so that P = 1
/F.
We measure the frequency in Hz. 1 Hz = 1 repeat per second.