Mechanical energy swing because of the work done by the pendulum to oppose these non-conservative forces. That the loss of mechanical energy in a system always resulted in an increase of the system's temperature has been known for a long time, but it was the amateur physicist James Prescott Joule who first experimentally demonstrated how a certain amount of work done against friction resulted in a definite quantity of heat which should be conceived as the random motions of the particles that comprise matter. This equivalence between mechanical energy and heat is especially important when considering colliding objects. In an elastic collision,
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