Peter(Skyward series) is a pilot on a far way planet, with similar gravitational

Peter(Skyward series) is a pilot on a far way planet, with similar gravitational
forces as Earth. he is going through pilot training. A motor spins an insulated container she is
in (total mass of 100 kg) around on a 4 m long arm at 250 rpm. The coefficient of kinetic friction
between the container and the ground is 0.30.
a) What is the force due to friction of this system? What direction does it point? (Think
carefully, because this is not the same as a car on a curve)
b) After the motor stops, what is the angular acceleration of the container as it comes to
rest?
c) After the motor stops, how long does the container take to come to rest?