The SI unit of momentum is kg m s-1. It can be understood from the equation of momentum itself:
Since p = mv
Therefore, in terms of units: p (units) = kg ms-1
Another standard unit of momentum used is Ns. Though it may seem different, we can actually prove that Ns and kg ms-1are equivalent:
p (units) = N s
N (Newtons) is the unit of force, and that can be expanded as follows:
Since: F = m a
In terms of units: N = kg ms-2
Therefore: p (units) = kg ms-2s
= kg ms-1
