Everyone enjoys the thrill of roller coasters, but not everyone takes the time to realize how they relate to physics. Roller coasters relate to physics because of the potential engery and the kinetic energy they use. As well as gravity, and using forces.
A roller coaster uses both potential energy and kinetic energy. It stores the energy as the roller coaster is inclining up the hill because of the gravity that is pulling it down creating a greater distance. As the potential energy is released once it has reached the top of the hill, kinetic energy takes over as it is going up the hill. Roller coasters tend to be converting potential energy and kinetic energy throughout the entire ride. For example, when there is a small hill somewhere on the ride, the train will store potential energy again as it is going up that hill until it goes back down. Gravity tends to do the same thing throughout the entire ride, but in different ways. If the roller coaster were to be moving up the hill, then gravity will be pulling the back of the train so it decelerates. If the roller coaster were to be moving down the hill, then gravity will be pulling the front of the train so it accelerates.