Question

A 2.0-kg solid cylinder of radius 0.5 m rotates at a rate of 40 rad/s about its cylindrical axis. What power is required to bring the cylinder to rest in 10 s?

Answer 1

\[P = \frac{W}{t}\]
\[ \quad W = \Delta KE\]
\[ \qquad KE_{rot} = \frac{1}{2}I\omega^2\]
\[\ \ \ \qquad I_{cyl} = \frac{1}{2}MR^2 \]

\[P = \frac{\frac{1}{2} \left( \frac{1}{2}MR^2 \right) \omega^2}{t} \]

Answer 2

Nice.