Afan 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

The average angular acceleration of the fan is

The number of revolutions after time is given by

Acceleration is assumed to be constant, so and over the 2 second interval we have

so the answer is A.

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.