Energy transfers

There are energy transfers going on all the time - whenever a system changes there is a change in the way some or all of the energy is stored.

Boat suspended from column, swings in circular arc. Highest point: no kinetic energy,  max gravitational potential energy. Lowest point: max kinetic energy, minimum gravitational potential energy.

A swinging pirate ship ride at a theme park.

Kinetic energy is transferred into gravitational potential energy.

Transferring energy

Energy is transferred by one of the following four types of energy transfer:

  • mechanical work – a force moving an object through a distance
  • electrical work – charges moving due to a potential difference
  • heating – due to temperature difference caused electrically or by chemical reaction
  • radiation – energy transferred as a wave, eg light, infrared, sound - light radiation and infrared radiation is emitted by the Sun.

Doing 'work' is the scientific way of saying that energy has been transferred. For example, a grazing cow, a firing catapult and a boiling kettle are all doing 'work', as energy is being transferred.