AP Physics Warm-up #17

A pulley is accelerated uniformly from rest at a rate
of 8.0 rad/s². After 20. s the acceleration stops and
the pulley runs at a constant speed for 2.0 minutes.
Then the pulley uniformly comes to rest after a
further 40. s. Find (a) the angular velocity after the
initial acceleration, (b) the rate of angular acceleration
when returning to rest, and (c) the total number of
revolutions made by the pulley.