Question

A ball hits a vertical wall horizontally at 10 m/s and bounces back at 10 m/s, then

• 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 1

Answer: (C)

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