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 Polytechnic University economics. Dalian Polytechnic University Dalian Polytechnic University () is a university in Dalian, Liaoning. The school was founded in 1958 in Shenyang as the Shenyang Institute of Light Industry (). In 1970, it was transferred to Dalian, and renamed as the Dalian Institute of Light Industry (). In 2006, it was promoted in 2006 from the rank of institute to the rank of university. It is the only institution of higher education in northeast of China specializing in light industry, food, textiles and art design. There are about 15,000 students on the campus. Subjects taught include engineering, science, arts, management,