Two friction wheels A and B are both rotating freely at 300 rpm counterclockwise when they are

Question:

Two friction wheels A and B are both rotating freely at 300 rpm counterclockwise when they are brought into contact. After 12 s of slippage, during which each wheel has a constant angular acceleration, wheel B reaches a final angular velocity of 75 rpm counterclockwise. Determine

(a) The angular acceleration of each wheel during the period of slippage,

(b) The time at which the angular velocity of wheel A is equal to zero.