Engine (such as pneumatic motors), springs (clockwork motors) and elastic bands. Historic military siege engines included large catapults, trebuchets, and (to some extent) battering rams were powered by potential energy. A pneumatic motor is a machine that converts potential energy in the form of compressed air into mechanical work. Pneumatic motors generally convert the compressed air to mechanical work though either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor or piston air motor. Pneumatic motors have found widespread success in the hand-held
Electric potential energy terms of the electric field in the form where formula_13 is the displacement of the electric field within a dielectric material and integration is over the entire volume of the dielectric. The total electrostatic potential energy stored within a charged dielectric may also be expressed in terms of a continuous volume charge, formula_14, where integration is over the entire volume of the dielectric. These latter two expressions are valid only for cases when the smallest increment of charge is zero (formula_16) such as dielectrics in the presence of metallic electrodes or dielectrics containing many charges. Electric potential energy Electric potential