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Worksheet: Wind Power


A volume of air moving through a wind turbine has a mass of 1 . 5 × 1 0 6 kg. If the air is moving at 5 m/s, what is the kinetic energy of the volume of air? Give your answer in megajoules to 2 significant figures.


What type of electric current do wind turbines produce?

  • ADirect current
  • BRectified alternating current
  • CPulsating current
  • DAlternating current


Wind turbines convert the energy of the moving air to energy.

  • Agravitational potential, kinetic
  • Bkinetic, gravitational potential
  • Cgravitational potential, electrical
  • Dkinetic, electrical
  • Ethermal, chemical


The graph shows the power output of a particular type of wind turbine against the wind speed. The table shows data for the wind speed at three different sites as measured on five consecutive days.

Calculate the average wind speed for each site over the five days on which the wind speed was measured, and use this information to determine which site will produce the largest power output if a wind turbine is placed there.

Wind Speed (m/s)
Day 1 Day 2 Day 3 Day 4 Day 5
Site A 6.5 5.9 7.0 3.5 4.0
Site B 1.1 2.8 3.1 2.4 4.1
Site C 8.5 4.6 7.1 4.2 5.5
  • ASite B
  • BSite A
  • CSite C


The installed capacity of a wind turbine is the maximum power output that it can produce.

What is the installed capacity of a wind farm containing 180 turbines if the installed capacity of one wind turbine is 3.6 MW?

Which of the following is the main reason why a wind farm does not achieve its installed capacity most of the time?

  • AThe wind speed is not constant; thus, wind turbines are not always producing their maximum power output.
  • BWind turbines become less efficient over time; thus, the maximum power output that they can produce decreases over time.
  • CA lot of energy is lost to heat in the transmission of the electrical current from the wind farm to where it connects to the electricity grid.
  • DA lot of energy is lost to heat in the generators in the wind turbines; thus, the actual power output of a wind farm is always lower than the installed capacity.
  • EWind turbines are unreliable and often break; thus, most of the time not all of the turbines on the wind farm are operating.