Energy Transfers 01
The Law of Conservation of Energy states that energy can be transferred from one type to another, it can't be created or destroyed. This is actually quite useful as it means that we can make things happen. An example of this is getting to school by bus. The bus has a tank of fuel (e.g. diesel). This is a store of chemical energy. The engine of the bus transfers the chemical energy into heat energy by burning it. This heat energy is then converted into kinetic energy as the burning fuel causes the pistons to move up and down. The kinetic energy is used to turn the bus wheels. We would say that the MAIN energy change for the bus is chemical energy to kinetic energy because that is the form of energy that we want.
No energy change is one hundred percent efficient. In the case of the bus, some of the heat energy heats up the engine and does not help to move the pistons. It is wasted. Some of the heat energy is lost through the exhaust pipe - more is wasted. Still more of the kinetic energy is wasted as heat because of friction between moving parts. In fact, only about a third of the stored chemical energy becomes kinetic energy. The most common wasted energy is heat. This spreads out into the environment and cannot be used anymore.
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