We sometimes encounter examples where a large force acts for a very short duration producing a finite change in momentum of the body. For example, when a ball hits a wall and bounces back, the force on the ball by the wall acts for a very short time when the two are in contact, yet the force is large enough to reverse the momentum of the ball. Often, in these situations, the force and the time duration are difficult to ascertain separately.
However, the product of force and time, which is the change in momentum of the body remains a measurable quantity. This product is called impulse:
- Impulse = Force × time duration = Change in momentum
A large force acting for a short time to produce a finite change in momentum is called an impulsive force.
