Energy Key Terms

Kinetic energy definition

The energy an object has because it is moving

Gravitational potential energy definition

The energy an object has because of its position

Elastic potential energy definition

The energy stored in a springy object when you squash or stretch it

Thermal energy definition

The energy a substance has because of temperature

Chemical energy definition

The energy stored in fuels, foods and batteries

Conservation of energy definition

Energy cannot be created or destroyed, only transferred

Work done definition

The energy transferred by a force

Dissipation definition

The process of energy being transferred or lost to the surroundings

Friction definition

A force that opposes movement

System definition

An object or group of objects

Closed system definition

An isolated system where no energy transfers take place into or out of the energy stores in the system

Useful energy definition

Energy in the place it is wanted in the form that it is needed in

Wasted energy definition

Energy that is not usefully transferred, usually as thermal

Energy transfer pathways

• Heating

• Waves

• Electric current

• Force when it moves an object

A falling object:

• Decreases GPE store

• Increases KE store as falls

• Waste energy transferred as thermal and sound

Carbon neutral definition

A process by which no extra carbon is released to the atmosphere

Machines waste energy…

Due to friction between moving parts, air resistance, electrical resistance and noise