# Chapter 10 - Rotation - Problems - Page 287: 9b

Angle it rotates in coming to rest $= 18.9$ $rad$

#### Work Step by Step

The formula to be used here is: $\omega_{f}^{2} = \omega_{o}^{2} + 2\alpha(\theta-\theta_{o})$ By arranging the equation, we make $(\theta-\theta_{o})$ the subject of formula: $(\theta-\theta_{o}) = \frac{\omega_{f}^{2}-\omega_{o}^{2}}{2\alpha}$ Substituting the values in formula and solving: $(\theta-\theta_{o}) = \frac{0^{2}-(12.6)^{2}}{2\times (-4.2)}$ $(\theta-\theta_{o})=18.9$ $rad$

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.