A ball of mass 50 g moving at a speed of 2.0 m/s strikes a plane surface at an angle of incidence `45^0`. The ball is reflected by the plane at an equal angle of reflection with the same speed. Calculate (a). the magnitude of the change in momentum of the ball (b). the change in the magnitude of the mometum of the ball.

Answer

(a) (0.14 kg. m/s) `hati` ; (b) There is no change in the magnitude of the momentum of the ball ; (c ) Since the wall remains motionless , its initial and final momenta are zero , and hence there is no change in the magnitude of its momentum .