A Machinist Turns the Power on to a Grinding Wheel,at

Multiple Choice

A machinist turns the power on to a grinding wheel,at rest,at time t = 0 s.The wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 29 rad/s.The wheel is run at that angular velocity for 27 s and then power is shut off.The wheel slows down uniformly at 2.7 rad/s² until the wheel stops.In this situation,the average angular velocity in the time interval from t = 0 s to t = 25 s is closest to:

A) 17 rad/s
B) 15 rad/s
C) 13 rad/s
D) 11 rad/s
E) 8.7 rad/s