The roller coaster has a potential energy of 1,500 J and a kinetic energy of 500 J as it begins its descent, making its total energy 2000 J. As the coaster approaches ground level, its kinetic energy rises to 1,100 J, and its potential energy falls to 500 J. Ultimately, at the base of the hill while it moves on the ground, its kinetic energy is 2000 J.