For instance, in SI units, energy is measured in joules, and one joule is defined mechanically, being the energy transferred to an object by the mechanical work of moving it a distance of 1 metre against a force of 1 newton.nergy is also transferred from potential energy () to kinetic energy () and then back to potential energy constantly. This is referred to as conservation of energy. In this closed system, energy cannot be created or destroyed; therefore, the initial energy and the final energy will be equal to each other.