Question 11In GWA 3 find the mean power density W/m^2 and mean wind speed at 100m for the 10% of the windiest areas of Denmark.

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%

At a wind farm, one turbine (A) is subjected to average wind speeds of 6.0 m/s. An identical turbine (B) at this site is subject to average wind speeds of 7.2 m/s.Determine the expected %  increase in power generated by turbine B with respect to turbine AExpress your answer to 3 significant figures

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.

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

A GSM1800 cell tower antenna is transmitting 20W of power in the frequency range of 1840 to 1845MHz. The gain of the antenna is 17dBi. Find the power density at a distance of  50m. Select one:a. 31.8m W/m2b. 41.8m W/m2c. 21.8m W/m2d. 51.8m W/m2