Suppose a revolving door at the bamk is spinning around once every 5 seconds. As you walk through, you push on the door for 2 seconds, which increases the rotational speed so that it rotates once a second. What was the rotational acceleration due to your push?
Vo = 1rev/5s * 6.28rad/rev=1.256 rad/s.
V = 1rev/s * 6.28rad/rev = 6.28 rad/s.
a=(V-Vo)/t=(6.28-1.256)/2=2.51 rad/s^2