Momentum and Newtons Laws of Motion

Newton's First Law of MotionAn object remains at rest or in uniform motion unless acted on by a force
Newton's Second Law of MotionThe rate of change of momentum of an objectis proportional to the resultant force on it.

F

α

m(v - u)      t

=

ma

for constant mass.The resultant force is equal to the rate of change of momentum.
If m changes at a constant rate then F = vΔm/Δt
The impulse of a force is defined as the force × the time for which the force acts.Impulse = FΔt = Δ(mv)So the impulse of a force acting on an object is equal to the change of momentum of that object.