21) A machinist turns on the power on to a grinding wheel at time t=0s. The wheel accelerates uniformly from rest for 10 s and reaches the operating angular speed of 58 rad/s. The wheel is run at that angular velocity for 30 s, and then power is shut off. The wheel slows down uniformly at 1.4 rad/s until the wheel stops. What is the total number of revolutions made by the wheel in this situation?