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 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 on technology and applied science, it has grown very rapidly ever since. It is now one of the leading universities in Northeast China. Students of DLNU have won numerous awards in various scientific and technological competitions, including winning Mathematical Contest in Modeling (MCM) 2005, representing China to compete in Robocup 2007, Winning Microsoft Imagine Cup in China 2008 and Second Price internationally