There are a couple of things happening while the coaster goes from the top of the hill to the bottom:
- The coaster loses gravitational potential energy.
- The coaster's loss in potential energy becomes its gain in kinetic energy.
- The coaster's gain in kinetic energy causes it to speed up.
- Maybe the coaster is also losing some of its newly gained kinetic energy to friction due to contact between the coaster's internal components and air resistance.
