A Fan Rotating with an Initial Angular Velocity of 1000

Multiple Choice

A fan rotating with an initial angular velocity of 1000 rev/min is switched off. In 2 seconds, the angular velocity decreases to 200 rev/min. Assuming the angular acceleration is constant, how many revolutions does the blade undergo during this time?

A) 10
B) 20
C) 100
D) 125
E) 1200