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 96 rad/s.The wheel is run at that angular velocity for 40 s and then power is shut off.The wheel slows down uniformly at 1.5 rad/s² until the wheel stops.In this situation,the time interval of deceleration is closest to:

A) 64 s
B) 62 s
C) 66 s
D) 68 s
E) 70 s