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 EDIE] 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 fn'ction. a} If the starting height of this n'de is ED m {position A}, determine the gravitational potential energy of the roller coaster car at this point. b} Determine the total mechanical energy possessed by the car at 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