If a roller coaster train has a potential energy of 1,500 J and kinetic energy of 500 J as it starts to travel downhill, its total energy is___J.

Once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 J, and its potential energy decreases to ___J.

When the train reaches the bottom of the track and is traveling along the ground, its kinetic energy is___J.