Chapter 3, Problem 35A

Suppose you place a ball in the middle of a wagon that is at rest and then abruptly pull the wagon forward. Describe the motion of the ball relative to the ground and the wagon.

To determine

To explain: The motion of the ball relative to the ground and the wagon.

Answer to Problem 35A

Relative to ground the ball is moving and relative to the wagon the ball is resting.

Explanation of Solution

Introduction:

A body is said to be in motion when its position changes with time.

As the wagon moves, the ball kept on the wagon also moves with a velocity same as that of the wagon relative to ground . Since the wagon changes its position relative to ground, the ball also changes its position relative to the ground. Therefore, relative to ground one can say the ball is moving.

Since the ball is at rest on the wagon, relative to wagon the ball is not changing its position. Therefore, ball is at rest relative to the wagon.

Conclusion:

The ball is in motion relative to ground whereas it is at rest relative to the wagon.