A ball hits a vertical wall horizontal at 10 m/s bounces back at 10 m/s

Options

A. There is no acceleration because `10(m)/(s)-10(m)/(s)=0`
B. There may be an acceleration because its initial direction is horizontal
C. There is an acceleration because there is a momentum change
D. Even though there is no change in momentum there is a change in direction. Hence it has an acceleration

Answer

C

Explanation

As the ball bounces back with same speed so change in momentum = 2 mv
and we know that force = rate of change of momentum i.e. force will act on the ball so there is an acceleration