the transformation in physical systems of part of the energy of an ordered process (for example, electrical energy) into energy of a disordered process—in the final analysis, thermal energy (such as joule heat). In mechanical systems, the transformation of part of the system’s mechanical energy into other forms, such as heat, occurs as a result of the presence of forces of resistance; dissipation of energy in the atmosphere is the transformation of part of the kinetic energy of the wind into heat under the influence of internal friction.