Task 4 In this task, you will use your knowledge about the law of conservation of energy from unit 3 to analyze the following situation involving a roller coaster. The roller coaster car has a mass of BUD kg. Assume the roller coaster car starts from rest at position A, before falling down the hill and moving through the rest of the ride [without any added propulsion}. Assume no friction. a} If the starting height of this ride is 2U m [position A}, determine the gravitational potential energy of the roller coaster car at this point. In} Determine the total mechanical energy possessed by the carat point D. Explain your reasoning. c} At which position will the roller coaster car have the greatest speed\"? Explain your reasoning. Determine the speed at this location