Mechanical energy nonconservative forces, like frictional forces, will be present, but often they are of negligible values and the mechanical energy's being constant can therefore be a useful approximation. In elastic collisions, the mechanical energy is conserved but in inelastic collisions, some mechanical energy is converted into heat. The equivalence between lost mechanical energy (dissipation) and an increase in temperature was discovered by James Prescott Joule. Many devices are used to convert mechanical energy to or from other forms of energy, e.g. an electric motor converts electrical energy to mechanical energy, an electric generator converts mechanical energy into electrical energy and a
Dalian Minzu University . Dalian Minzu University has a good reputation in both engineering and science programs. The university also offers programs in business, economics, arts, and management. It has 40 bachelor's degree programs and 14 colleges, including: The campus is large and has comprehensive modern teaching and research equipment. Fifteen state and provincial key laboratories have been established one after another throughout the years. Dalian Minzu University Dalian Minzu University () is located in Dalian, Liaoning, People's Republic of China and directly supervised by the State Ethnic Affairs Commission. Dalian Minzu University was founded in 1997. As the only Nationalities University focusing