What causes a roller coaster to "lose" energy and stop? What force does it lose energy to? Give a detailed explanation that is easy to understand.

Roller coasters work by utilizing its potential energy. Potential energy is "lost" as the cars lose height, subsequently gaining kinetic energy as revealed by increased speeds (and loop the loop). As the cars of the roller coaster course through the changing heights, it constantly swaps between potential and kinetic energy. Theoretically, this process could be endless. However, energy is continually "lost" because of dissipative forces such as friction and air resistance.