If the lowers his hand so as to lengthen the duration of the force, the same change of momentum will need a comparatively smaller force (figure b) and so he will not feel the pinch of catching the ball.įor the same reason when a man jumps from a high wall on the side concrete road he hurts himself more seriously than when he jumps from the same wall on a heap of sand. The force being very large he (the fielder) will feel severe pain, particularly in the bare hands. If the same ball is to be stopped in the same interval Δt by a fielder he must apply the same average impulsive force of figure (a).

When a cricket ball is hit by a bat, it exerts an impulsive force on the ball and the impulse of the force on the balls is so great that it moves in the opposite direction with tremendous speed. At the instant t the elementary impulse is F.dt. The total impulse of the force during the interval for which it acts is given by the summation of the impulse from instant to instant. The plot of an impulsive force is a curve which is zero in the beginning and the end of the interval showing a peak value at some intermediate instant. In fact an impulsive force is variable force. Thus the impulse of an impulsive force = change in momentum = vector FΔt. In contrast, an impulse is the effect of an impulsive force acting over a short duration it gives the change in momentum of a body brought by a sudden force. A greater force produces a higher acceleration. The impulse of an impulsive force is the great change in momentum produced by it. Impulsive Force A force determines the acceleration (rate of velocity change) of an object. Where vector F is the average force during the short interval Δt and vector a is the average acceleration produced.

The force experienced by the coil of a moving coil galvanometer due to sudden flow of current is an impulsive force. When we kick a ball, the force on the ball is an impulsive force. A great force acting for a very short interval of time on a body is called an impulsive force.There are numerous examples of impulsive forces.

Impulse and impulsive force