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
Xinggong Subdistrict, Dalian Xinggong Subdistrict, Dalian Xinggong Subdistrict () is a township-level division of the north of the Shahekou District of Dalian, Liaoning, China. Xinggong Subdistrict is first and always well known as Xinggong Street or Xinggong Jie () because of the important and famous street which Dalian people always call by "Xinggong Street" instead of "Xinggong Subdistrict" where Xi'an Road Commercial Zone is. Xinggong Subdistrict was also an important Japanese (Kwantung Leased Territory) machi called by where was. The area of Xinggong Subdistrict is 4 km. It has 16 villages/communities like Xingxin Community, and 256 neighborhoods/community groups. Until 2016, the population of