Energy

What is the rule about energy

Energy can be transferred usefully, stored, or dissipated, but it can never be created or destroyed

Name all the energy stores

Kinetic

Thermal

Gravitational potential

Chemical

Elastic potential

Electrostatic

Magnetic

Nuclear

Explain kinetic energy store

Moving objects have energy in this store

Explain the thermal energy store

Hot objects have energy in this store

Explain gravitational potential energy store

Elevated objects have energy in this store

Explain chemical energy

Food and anything living and chemicals that may be reactive have energy in this store

Explain the elastic potential energy store

Objects that have been stretched or compressed have energy in this store

Explain the electrostatic energy store

Any charge that interacts with another charge

Explain the magnetic energy store

Magnetic objects interacting with each other

Explain the nuclear energy store

Energy released in nuclear reactions

Name the 4 energy transfers

Mechanical

Electrical

By heating

By radiation

Explain mechanical transfers

Energy transferred when a force acts on an object

Explain electrical transfers

A charge moves through a potential difference

Explain energy transfers by heating

Energy transferred from a hotter object to a colder object

Explain energy transfered by radiation

Energy transferred by waves

Explain efficiency in energy

Tells us how much energy is transferred usefully snd how much is wasted

Equation for efficiency

Energy transferred usefully / total input energy

×100

What is a sankey diagram

A diagram to show where the energy is going

What are waste energy transfers

When energy is transfered to the surroundings and ‘lost’ reducing efficiency

How can waste transfers be reduced

Using high quality bearings to reduce friction.

Use lube to reduce friction

Use low resistance wires to reduce heating

Cooling fans to stop over heating