Potential energy is the energy that something has because of its position or because of the arrangement of its parts. A baseball in flight has potential energy because of its position above the ground. A carbohydrate molecule has potential energy because of the arrangement of the atoms in the molecule.

A diver standing on a platform above the water has potential energy because of a capacity for doing work by jumping off. The higher the diver is above the water and the greater the diver's mass, the greater the potential energy—that is, the capacity for doing work. It is the gravitational force that pulls the diver downward and into the water. For this reason, the potential energy of the diver is called "gravitational potential energy." As an equation, gravitational potential energy (U) measured in joules (J) is given by U = mgh, where mis the mass...