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GCSE Questions: Energy Sources

Q8. The sketch below shows a wind turbine.

(a) At a particular wind speed, a volume of 2.3 × 104 m3 of air passes the blades each second.

The density of air is 1.2 kg/m3.

Calculate the mass of air passing the blades per second.

[3 marks]

(b) The power output of the turbine is directly proportional to the kinetic energy of the air passing the blades each second. Describe the effect on the power output when the wind speed is halved.

[3 marks]

(c) At a different wind speed, the wind turbine has a power output of 388 kW.

The mass of air passing the wind turbine each second is 13,800 kg.

Calculate the speed of the air passing the blades each second.

Assume that the process is 100% efficient.

[4 marks]

(Total 10 marks)