Wind provides an increasingly important source of renewable energy in certain locations of the world. In fact, wind was the second largest renewable energy source worldwide (after hydropower!) and provided more than six percent of global electricity in 2020; in the U.S. that number was 8.4\%. Suppose that wind turbines can convert up to 30% of the kinetic energy of incoming wind blowing through their blades into electricity (i.e., useful shaft work). In the following, we will analyze the power output of a wind turbine with a diameter of d=80m placed at an offshore location where the wind blows steadily at an average speed of 20 knots. Explicitly state all relevant approximations or assumptions. (a) Draw a diagram that includes appropriate elements for assessing the amount of work extracted from the wind turbine. Your diagram should have annotated any known or approximated properties. What is your system and surroundings? What kind of boundary divides these two? Hint: In terms of system setups, there are at least two reasonable approaches. You may choose your system to be a fixed amount of air that you follow during the process (this would represent a closed system). Otherwise, if you choose a system defined by a control volume surrounding the wind turbine, you should adopt an open-system approach. (b) How much electrical work can be produced from the wind turbine? (c) By how much must the wind be slowed down to produce the amount of work indicated above? Do you suppose this wind speed is an over- or underestimate and why