A physics instructor is demonstrating rotational motion with a bicycle wheel. The wheel has a radius of R = 40.0 cm, a mass of m = 4.00 kg, and a rotational inertia of I = 0.40 kg*m^2. The instructor initially spins the wheel so that it is rotating 5.00 revolutions per second.

a) What is the initial angular velocity of the wheel?

b) What is the initial kinetic energy of the rotating wheel?

c) What is the value of the wheel's angular acceleration? d) How long does it take the wheel to come to rest while the frictional force is being applied?