Created Wednesday 25 May 2016

Dimension: Classification/Nature of physical quantity
Unit: Standard of measurement of a physical quantity

distance -> L
time -> T
mass -> M

Dimensional homogeneity means only quantities with the same dimensions may be compared, equated, added, or subtracted.
Basically only stuff with same dimensions can be used mathematically.

Quantity SI Unit Other SI Unit Dimension
Force kgms^-2 N MLT^-2
Energy kgm^2s^-2 J ML^2T^-2
Power kgm^2s^-3 W ML^2T^-3
Momentum kgms^-1   MLT^-1
Impulse kgms^-1   MLT^-1