The mean power output of a large wind farm is 520 MW520\text{ MW}520 MW, which is enough to supply power to 400 000400\,000400000 homes.
Calculate the mean power needed for 1 home. Give your answer in watts.
Some of the kinetic energy of the wind is wasted as thermal energy in the gears and bearings of the turbines. An engineer applies a lubricant to these moving parts. Explain how applying a lubricant affects the efficiency of the wind turbines.
Practise AQA GCSE Physics Conservation and dissipation of energy with exam-style questions for Foundation and Higher tier. 29 questions covering Energy transfers in a system and Efficiency, matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.