Answer
$250\ rad$
Work Step by Step
Given:
initial angular velocity of fly wheel $ω_o=25 rad/s$
time taken to stop is t=20 s
The angle through which the fly wheel rotates is:
$\theta =(\frac{ω+ω_o}{2})Δt$
$\theta =(\frac{0+25}{2})(20\ s)$
$\theta= 250\ rad$
