Roller Coasters are driven almost entirely by basic inertial, gravitational, and centripetal forces, all manipulated in the service of a great ride. A roller coaster is like a passenger train, but unlike a passenger train, a roller coaster has no engine or power source pf its own. For most of the ride, the train is moved by gravity and momentum.
The components of the roller coaster are the chains, catapult launch lift, and brakes. The chain is fastened in a loop, which is wound around a gear at the top of the hill and another one at the bottom of the hill. A catapult launch lift sets the train in motion. Instead of dragging the train up a hill to build potential energy, these systems start the train off by building up a good amount of kinetic energy in a short amount of time. Brakes stop the train at the end of the ride or an emergency. Brakes aren't built into the train, but on the track. A series of clamps are positioned at the end of the track and a few other braking points.
The physics of the roller coaster is when a roller coaster goes downhill, gravity takes over and all the built up potential energy changes into kinetic energy. A force on the ride is when your body will keep going at the same speed in the same direction unless some other force acts upon you to change that speed or direction.