Chapter 9, Problem 6PT

To determine

To find the number of seconds that pass before Isabel returns to her starting position.

Answer to Problem 6PT

  $12\text{seconds}$

Explanation of Solution

Given:

The counterclockwise rotation about its center ${60}^{\circ }$ every $2$ seconds.

Calculation:

The one full rotation is ${360}^{\circ }$ , now divide this rate to find the time as follows-

  $\begin{array}{l}{360}^{\circ }÷\frac{{60}^{\circ }}{2}\text{seconds}\\ ={360}^{\circ }\times \frac{2}{{60}^{\circ }}\text{seconds}\\ =12\text{seconds}\end{array}$