The impulse is defined as I = Ft, but this formula does not compute the impulse in all cases, only for the impulse of constant forces. Impulse is a physical quantity that describes the cumulative effect of a force on a body over time. The impulse of force is a process quantity. When we talk about impulse, we have to specify which force is the impulse at which time.

The impulse of a constant force is the product of the force and the time it acts on it. Impulse describes the physical quantity that acts on a particle for a period of time and is the reason for changing the mechanical motion state of a particle.