1. A wind turbine with a radius of 8 m operates in a wind of 54 km/h. The efficiency of converting the wind energy into work is 40%. Find the power of the turbine. 2. Solar radiation incident on a...

1. A wind turbine with a radius of 8 m operates in a wind of 54 km/h. The efficiency of converting the wind energy into work is 40%. Find the power of the turbine.

2. Solar radiation incident on a normal surface is 1300 W/m2 of which 70% is absorbed by the collector. Find the energy absorbed by a collector of 4 m2 during 3 h of operation. Express your answer in a. kilojoules. b. kilocalories. c. British thermal units.