ENERGY TRANSFORMATION IN THE ROLLER COASTER Energy is the ability to do work, and it exists in different forms. Two fundamental types of mechanical energy are potential energy (PE) and kinetic energy (KE). Potential Energy (PE) is stored energy due to an object's position or state. In a roller coaster, this is highest at the top of a hill, where the ride is elevated but not yet in motion. Kinetic Energy (KE) is the energy of motion. The faster an object moves, the more kinetic energy it has. In