Question

A ball of mass 'm' moves normal to a wall with a velocity 'u' and rebounds with the same speed. The change in momentum of the ball during the rebounding is

• A. 2mu towards the wall
• B. 2mu away from the wall
• C. zero
• D. mu away from the wall

Answer 1

Answer: (B)

2mu away from the wall

If the collision of the ball and the wall is elastic one then the change in the momentum of the ball after collision is $=mu-(-mu)=2mu$ away from the wall.