Betz's law states that only 53% of the kinetic energy transported by wind can be converted to

Question:

Betz's law states that only 53% of the kinetic energy transported by wind can be converted to shaft work by a perfect wind turbine. For a 50 m diameter turbine in a 20 mph wind, what is the maximum possible shaft power (W⋅sh)? Assume density of air to be 1.1 kg/m3. (1 mph = 0.447 m/s).