Quantities, units and symbols
It is most important that when you write down a quantity you give it the correct units
and use the correct symbol for those units. The following table shows most of the
common quantities.
Quantity measured |
Name of unit |
Symbol for unit |
Length (L) |
metre |
m |
Mass (m) |
kilogram |
kg |
Time (t) |
second |
s |
Velocity (speed) (v) |
metres per second |
m/s |
Acceleration (a) |
metres per second per second |
m/s2 |
Momentum |
Newton seconds |
Ns |
Force (F) |
Newton |
N |
Energy |
joule |
J |
Work |
joule |
J |
Power (P) |
watt |
W |
Density (ρ) |
kilograms per metre cubed |
kg/m3 |
Pressure |
Pascal, Newtons per metre squared |
Pa, N/m2 |
Frequency (f) |
Hertz |
Hz |
Temperature |
degrees centigrade, Kelvin |
oC, K |
Specific heat capacity |
Joules per kilogram per degree C |
J/kgoC |
Specific latent heat |
joules per kilogram |
J/kg |
Charge (Q) |
coulomb |
C |
Current (I) |
ampere (amp) |
A |
Voltage (V) |
volt |
V |
Potential difference |
volt |
V |
Resistance (R) |
ohm |
Ω |
A VERSION IN WORD IS AVAILABLE ON THE SCHOOLPHYSICS USB