SMALL TIME interval, it is called IMPULSIVE force.An impulsive force does not remain constant, but changes first from zero to maximum and then from maximum to zero. In such a case, we measure the total effect of force.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 the change in momentum.The impulse of a force is a measure of the total effect of force.Impulse is a vector quantity and its direction is the same as that of force.SI unit of impulse is Newton-second or kg-m-s-1 and CGS unit is g.m/s