Question

define impulse. show that impulse of a force is equal to the change in momentum

Answer 1

When you apply a force for a certain amount of time, you create an impulse. In fact, that’s the definition of impulse — impulse equals the force applied multiplied by the time it was applied. Here’s the equation:

Impulse = Ft

Note that this is a vector equation because the force has a direction; therefore the impulse does as well. Impulse can be an important quantity when you’re solving physics problems because you can relate impulse to momentum, and you must work with momentum to solve most collision problems in physics.

Here’s an example of impulse in action: You’re playing pool, and you strike a pool ball with the cue. The cue may be in contact with the ball for only a millisecond, but there’s an observable result — the ball is now in motion. That is a result of impulse.

What are the units of impulse? You have force multiplied by time, so the unit is the Newton-second.

Answer 2

in simple definition
The impulse caused by a force during a specific time interval is equal to the body's change of momentum during that time interval: impulse, effectively, is a measure of change in momentum.