Energy conversion from potential energy (the energy of position or composition) to kinetic energy (the energy of motion) is illustrated by the diagram of a roller coaster. when the coaster is in position a, the potential energy is and the kinetic energy is . as the coaster moves to position b, the potential energy is and the kinetic energy is . as momentum carries the coaster into position c, the potential energy is and the kinetic energy is . finally as the coaster reaches position d, the potential energy is and the kinetic energy is

The following is an elaboration of the differences in potential and kinetic energies based on the diagram of the roller coaster: When the coaster is in position A, the potential energy is maximum and the kinetic energy is minimum. As the coaster moves to position B, the potential energy is minimum and the kinetic energy is maximum . As momentum carries the coaster into position C, the potential energy is minimum and the kinetic energy is maximum. Finally, as the coaster reaches position D, the potential energy is maximum and the kinetic energy is minimum.