Engine in thrust. Particularly notable kinds of engines include: Engine An engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines burn a fuel to create heat which is then used to do work. Internal combustion engines are heat engines that burn fuel in a combustion chamber to extract work from the pressure of expanding gases. Electric motors convert electrical energy into mechanical motion; pneumatic motors use compressed air; and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces
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