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,
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