Chapter 11, Problem 57A

(a)

To determine

Whether there is conservation of momentum when a clay ball is thrown at a hockey puck on ice and smashed clay ball and hockey puck stick together and move slowly.

Explanation of Solution

Introduction:

Momentum of body is mass times the velocity.It is vector quantity.

Clay ball and hock puck are stick together after collision.Hence, both bodies move with same velocity after collision, no unbalanced forces are act in the system. Momentum is conserved.

(b)

To determine

Where there is conservation of kinetic energy when a clay ball is thrown at a hockey puck on ice and smashed clay ball and hockey puck stick together and move slowly.

Explanation of Solution

Introduction:

Kinetic energy is the energy possessed by the object due to its motion.

When the clay ball collides on a hockey puck it loses some kinetic energy due to collisions and some energy due to adhesion of the ball to puck.It is an inelastic collision.

Conclusion:

Kinetic energy of a system not conserved.