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,
Energy policy of China provide renewable electricity to 3.5 million households in 10,000 villages by 2010. This is to be followed by full rural electrification using renewable energy by 2015. Although a majority of the renewable energy in China is from hydropower, other renewable energy sources are in rapid development. In 2006, a total of 10 billion US dollars had been invested in renewable energy, second only to Germany. In 2006, 16 million tons of corn have been used to produce ethanol. However, because food prices in China rose sharply during 2007, China has decided to ban the further expansion of the corn ethanol