Question

A particle of mass 'm' moving with velocity v strikes a horizontal surface at angle Ɵ with the vertical and rebounds with the same magnitude and at the same angle with the vertical.The magnitude in change of momentum is A) 2 mv cos Ɵ B) 2mv sin Ɵ C)2mv D) 0 Give reasons

Answer 1

initial y component of momentum is in the negative y direction.... final y component of momentum is in positive y direction....This is because a force is exerted by the surface on the particle in the y direction