A roller coaster car moves with an initial kinetic energy of 588 kJ. The car goes over a 15 m hill to then a drop 18 m below the starting point. It stops by compressing a spring with spring constant k = 25000 N/m. The mass of the roller coaster is 1500 kg. You can neglect the friction on the roller coaster. Consider a system consisting of the roller coaster, earth, and spring. k-25,000 N/m 15m 18 m ww A. What is the change in gravitational potential energy of the system, from the start to the top of the hill? B. What is the speed of the roller coaster when it is at the top of the hill? . What is the change in gravitational potential energy of the system, from the start to the bottom of the drop?