# More on Energy Transfer.

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In the last topic you only scratched the surface of all things energy transfer. By the time you've got through this one, you'll hopefully have no problem...

• Knowing that energy is transferred when a force moves an object.
• Being able to calculate the energy transferred when a force moves an object by a given distance.
• Understanding that you can use the same amount of energy to apply a big force over a short distance or a small force over a long distance.

Energy is Measured in Joules.

1) The standard unit for measuring energy is joules, J.

2) One joule is roughly the energy needed to lift an apple by 1 metre.

3) When a lot of energy is transferred, you can use kJ (a thousand joules).

Energy is Transferred When a Force Moves an Object.

• When a force moves an object through a distance, energy is transferred.
• Energy transferred is the same as work done.

1) If you want to move something, you need to supply some sort of force to it.

2) The thing putting in the force needs a supply of energy (e.g. from the chemical energy stores in fuel or