‘Impulse’ can be defined as:

the force acting on a body for a short time

The correct answer is option 3. the force acting on a body for a short time.

'Impulse' can be defined as the force acting on a body for a short time

Impulse (\(J\)) is the product of the force applied to an object and the time interval (\(Δt\)) during which the force is applied. It can be mathematically expressed as:

\[ J = F \cdot Δt \]

Impulse represents the change in momentum of the object and is equal to the integral of the force with respect to time. It is often associated with collisions or interactions where a force is applied to an object for a short duration, resulting in a change in its momentum. Therefore, the correct definition of impulse is the force acting on a body for a short time.