Chapter 7, Problem 13A

When can two kicks on a soccer ball produce a net force of zero on the ball?

To determine

The situation in which two kicks on a soccer ball produce a net force of zero on the ball.

Answer to Problem 13A

When the two kicks on the ball are equal in magnitude but opposite in direction.

Explanation of Solution

Introduction:

A force is defined as a push or a pull exerted on an object. A force is a vector quantity since it depends on the direction.

Now, suppose the kicks on the soccer ball is exerted in opposite directions but they have equal magnitude $F$ . Then, the net force on the ball will be,

  $\begin{array}{c}\overrightarrow{F}=\overrightarrow{F_1}+\overrightarrow{F_2}\\ =F+\left(-F\right)\\ =0\end{array}$

Conclusion:

Hence, when the kicks of same magnitude are exerted on the soccer ball in opposite direction, the net force on the ball will be zero.