A large grindstone wheel ( a solid cylindrical disk made of stone) has a mass of 30 kg. and a radius of 50 cm. It is spinning at an angular rate of 90 rev./min. A brake is applied at the edge of the disk and pushed against it with a force of 25 newton. If the brake coefficient of
friction is u=.65,
a) what is the torque acting on the wheel?
b) what is the angular acceleration of the wheel?
c) How many complete revolutions does it turn through before stopping?