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, B, D

Explanation

(a) `|Deltap|=sqrt(p_1^2+p_2^2-2p_1p_2cos 90^@)`
`=sqrt(p_1^2+p_2^2)`
`=sqrt((0.05xx2)^2+(0.05xx2)^2)`
`=0.14kg-m//s`
(b) Initial and final velocity of wall is zero. Therefore change in momentum is zero.