Mechanical energy mechanical energy of the colliding objects has been converted into an equal amount of heat. Thus, the total energy of the system remains unchanged though the mechanical energy of the system has reduced. A satellite of mass formula_4 at a distance formula_5 from the centre of Earth possesses both kinetic energy, formula_6, (by virtue of its motion) and gravitational potential energy, formula_7, (by virtue of its position within the Earth’s gravitational field; Earth's mass is formula_8). Hence, mechanical energy formula_9 of a satellite is given by If the satellite is in circular orbit, the energy conservation equation can be further
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