Chapter 4.1, Problem 4PP

To determine

To Explain: The reason for speeding up of a softball on falling after it reaches the maximum height when thrown upward.

Explanation of Solution

Introduction:

As per Newton’s second law of motion, a body accelerates when the net force on it is not zero and a body is at rest when the net force on it is zero.

When one throws a softball, it moves upwards with decreasing speed and reaches a maximum height where its speed becomes zero. After attaining this maximum height, the softball falls down with increasing speed because it moves in the same direction as that of the force of attraction of earth. This causes accelerated motion of the ball and it speeds up.

Conclusion:

When the ball falls back down after attaining maximum height, it speeds up because of acceleration due to gravity.