Explanation:
Mass of the wheel, m = 49 kg
Radius of the hoop, r = 0.73 m
Initial angular speed of the wheel, 
Final angular speed of the wheel, 
Time, t = 22 s
(a) If I is the moment of inertia of the hoop. It is equal to,



We know that the work done is equal to change in kinetic energy.



W = -1858.05 Joules
(b) Let P is the average power. It is given by :


P =84.45 watts
Hence, this is the required solution.