A wind turbine has an efficiency of 0.7. The wind provides 8000 J of kinetic energy to the blades of the wind turbine. How much useful energy will the wind turbine transfer? Use the equation below to help you. You may need to rearrange the equation.

Wind turbines can transform the energy in wind movement into clean electricity. What percentage of our global energy comes from the wind?0.8%2.4%11%

A wind column with a mass of 4 kg has an initial velocity of 40 m/s before interacting with a wind turbine. After the interaction, the wind has a velocity of 20 m/s. How much energy was transferred from the wind to the turbine? (Do not put commas to your answer.)

The wind velocity on the upstream side of a wind turbine is 3.4 m/s. If the turbine extracts 27% of the available kinetic energy, what is the wind velocity on the downstream side of the turbine in m/s? Please include one decimal place in your answer.

he power output of the turbine is directly proportional to the kinetic energy of the airpassing the blades each second.Describe the effect on the power output when the wind speed is halved.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________(3)Page 30 of 34Energy (H)PhysicsAndMathsTutor.com

Wind is incident on the blades of a wind turbine. The radius of the blades is 12 m. Thefollowing data are available for the air immediately before and after impact with the blades.Before AfterDensity of air 1.20 kg m–3 1.32 kg m–3Wind speed 8.0 m s–1 4.0 m s–1(a) Determine the maximum power that can be extracted from the wind by this turbine.