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Energy transfers

Different forms of energy can be transferred from one form to another.

Plants, animals and machines all transfer energy.

Energy transfer diagrams show each form of energy - whether it is stored or not - and the processes taking place as energy is transferred.

The energy transfer diagram below shows the useful energy transfer in a car engine.

You can see that a car engine transfers chemical energy, which is stored in the fuel, into kinetic energy in the engine and wheels.

This diagram shows the energy transfer for the useful energy transfer in an electric lamp.

You can see that the electric lamp transfers or converts electrical energy into light energy.

Note that these energy transfer diagrams are only showing the useful energy transfers.

However, when energy is changed some is always converted into less useful forms, or “wasted”.

Car engines are noisy and hot, and so some of the chemical energy is converted to heat and sound.

The electric lamp heats up and so some of the electrical energy is converted to heat energy.

In this simple circuit below there are two energy changes.

In the cell, a chemical reaction occurs and chemical energy is converted into electrical energy.

The lamp converts electrical energy to light energy.

In both the cell and the lamp there is wasted heat energy.

Sometimes your mobile phone feels warm.

In the battery, chemical energy is converted to electrical energy and heat energy.

The phone uses the electrical energy, and you feel the results of the wasted heat energy.

Some other energy transfers: