A body of mass 5 kg at rest is acted upon by a force. Its velocity changes to 6 ms^–1. Find its initial and final momentum in kg ms^-1.

Given Mass, m = 5 kg

Initial velocity, u = 0 m s⁻¹

Final velocity, v = 6 m s⁻¹

Initial momentum (p₁)

Since the body is at rest, its initial momentum is zero.

(∴ p = mass × velocity)

p₁ = 0

∴ Final momentum, (p₂)

p₂ = mv

p₂ = (5 kg) × (6 m s⁻¹) = 30 kg m s⁻¹