Impulse is defined as the product of the force (F) acting on an object and the time of action (t).

  1. Impulse is the product between the force, F with the time of impact, t.
  2. Impulse is also defined as the change in momentum.
  3. Impulse is a vector quantity.
  4. An impulse will cause velocity change of an object.


Formula of impulse

Impulse is the product of force and time.

Impulse = momentum change


A billiard ball weighing 0.25 kg is in a stationary state on a smooth billiard table. The ball is then given an impulse as much as 3.0Ns horizontally. What is the velocity of the ball after impact?

Mass of the billiard ball, m = 0.25kg
Initial velocity of the billiard ball, u = 0
Impulse = 3.0Ns
Final velocity, v = ?

Impulse = momentum change = mv – mu
(3.0) = (0.25)v – (0.25)(0)
3 = 0.25v
v = 3/0.25 = 12 m/s