Two objects,one less massive than the other,collide elastically and bounce back after the collision.If the two originally had velocities that were equal in size but opposite in direction,then which one will be moving faster after the collision?
A)The less massive one.
B)The more massive one.
C)The speeds will be the same after the collision.
D)There is no way to be sure without the actual masses.

Question

Quizplus · Accepted Answer

In an elastic collision, momentum and kinetic energy are conserved. Since the two objects have equal and opposite velocities before the collision, their total momentum is zero. After the collision, since the objects bounce back, their velocities will also be equal and opposite. However, the less massive object will have a greater change in velocity due to conservation of momentum. Therefore, it will be moving faster after the collision.

Two Objects,one Less Massive Than the Other,collide Elastically and Bounce