Question

A rotating wheel requires 5.00 s to rotate 30.0 revolutions. Its angular velocity at the end of the 5.00 s interval is 100.0 rad/s. What is the constant angular acceleration of the wheel?

Answer 1

average angular speed = Wav = 30 * 2pi/5 =37.7 rad/s
so
(w end + w begin)/2 = 37.7
(100 + w begin)/2 = 37.7
100 + w begin = 75.4
w begin = -24.6 rad/s
alpha = (w end - w begin)/t
= 124.6/5 = 25 rad/s^2