Answer
a) $\theta=1.21\times10^4rad$
b) $t=110s$
Work Step by Step
We have $\alpha=-2rad/s^2$, $\omega_0=220rad/s$ and $\omega=0$
a) The angle through which the flywheel turns is $$\theta=\frac{\omega^2-\omega_0^2}{2\alpha}=1.21\times10^4rad$$
b) The time for the flywheel to come to rest is $$t=\frac{\omega-\omega_0}{\alpha}=110s$$
