Question

A constant torque is applied to the rim of a grindstone (disk) whose radius is 0.6 m and mass is 2.5 kg.

a) What is the grindstone's initial moment of inertia?

b) Find the angular speed after the grind stone has made 12.0 revolutions if: i. the magnitude of the torque is uniform 36.0 N·m, and the grindstone starts at rest, then initially speeds up. ii. the magnitude of the torque is uniform 4.00 N·m, and the grindstone starts at 16 rad/s, then initially slows down.

c) What is the magnitude of the average friction force applied to the disk initially slowing it down (b-ii)?

Answer 1