## Essential University Physics: Volume 1 (3rd Edition)

$.4347$
We first find the angular velocity: $\omega = \frac{2\pi}{1.8}=3.491$ We now find the coefficient of friction: $\omega^2 A m_2 =\mu m_2g$ $\mu = \frac{\omega^2 A}{g}$ $\mu = \frac{3.491^2 (.35)}{9.81}=.4347$