A pulley os radius 2m is rotated about its axis by a force `F= (20 t- 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 `10kg m^2` the number of rotaitons made by the pulley before its direction of motion is reversed, is:

Options

A. more than 3 but less than 6.
B. more than 6 but less than 9.
C. more than 9.
D. less than 3.

Answer

A

Explanation

more than 3 but less than 6.