A Wind of Velocity 10 M/s Is Blowing Through a Wind

Multiple Choice

A wind of velocity 10 m/s is blowing through a wind generator with blade radius 5.00 metres. What is the maximum power output if 30.0% of the wind's energy can be extracted? $\rho$ air = 1.25 kg/m3.

A) 7.20 kW
B) 14.7 kW
C) 21.3 kW
D) 29.4 kW
E) 39.6 kW