# Momentum Multiple Choice Question

1. Apr 28, 2010

### Procrastinate

A boy travelling on a skateboard steps off the board perpendicular to its motion. After stepping off, the boy lands on the ground and comes to rest. Which one of the following statements is INCORRECT?

A The boy exerts an impulse on the ground on impact
B The ground exerts an impulse on the boy on impact
C The momentum possessed by the boy before the collision is shared with the earth
D The momentum possessed by the boy before the collision is transformed to heat

Would the answer be D because momentum is not a form of energy; rather, it is a measurement which shows the tendency of an object to move in its line of direction.

Furthermore, can the ground exert an impulse on objects such as bouncing balls, etc?

2. Apr 28, 2010

### kuruman

That is correct.
Yes. A bouncing ball exerts an impulse on the Earth and the Earth exerts an equal in magnitude but opposite in direction impulse on the ball. This is a consequence of Newton's Third Law.