A pulley of radius 2 m is rotated about its axis by a force F = ( 20t – 5t^2 ) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2, the number of rotations made by the pulley before its direction of motion if reversed, is

Q: A pulley of radius 2 m is rotated about its axis by a force F = ( 20t – 5t² ) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m² , the number of rotations made by the pulley before its direction of motion if reversed, is

(a) Less than 3

(b) More than 3 but less than 6

(c) More than 6 but less than 9

(d) More than 9

Ans: (b)