Question 9: What is impulse? How it is related to the change of momentum? (Or show that J = ∆P)

ANSWER

In many instances large forces act on bodies for a very small interval of time. In such cases, it is very difficult to make exact calculations. Therefore, we usually use the concept of impulse.

Definition: When large forces act for a very small interval of time, the phenomena is called impulse. It is represented by J.

Such a force is called impulsive force and the time as time of impact.

Mathematically,

Impulse = impulsive force * time of impact

If the force is a varying one, we take the average of the force then.

Relation between impulse and change in momentum

The relation can be derived by the Newton’s second law.

But

Put for ‘a’ in the first equation

This shows the relation between momentum and impulse.