on this cheat sheet
Everything on the GCSE Physics Energy Stores, Transfers & Conservation poster is written out below, section by section. Use it to search the sheet, copy parts into your own notes, or check a fact quickly.
The 8 energy stores
- Kinetic - energy of a moving object.
- Thermal - energy of an object due to the movement of its particles.
- Chemical - energy stored in chemical bonds (e.g. food, fuels).
- Gravitational - energy of an object raised in a gravitational field.
- Electrostatic - energy stored in objects with electric charge.
- Elastic - energy stored when an object is stretched or compressed.
- Magnetic - energy stored in a magnetic field.
- Nuclear - energy stored in the nuclei of atoms.
Store vs transfer
Store - where energy is kept. Transfer - how energy moves from one store to another.
4 ways energy can be transferred
| How it's transferred | Definition | Examples |
|---|---|---|
| Mechanically | A force moving an object | Gears, levers, pushing, pulling |
| Electrically | A current flowing in a circuit | Wires, motors, kettle |
| By heating | Energy passing between particles or bodies of different temperatures | Conduction, convection |
| By radiation | Energy carried by electromagnetic waves | Light, infrared |
Conservation of energy
Energy cannot be created or destroyed, only transferred between stores.
The total energy in a closed system always stays the same: total energy in = total energy out.
Useful vs wasted energy
Every transfer moves some energy to useful stores and some to wasted stores (usually the thermal store of the surroundings). The total amount of energy is the same - it just spreads out and becomes less useful.
Reducing wasted energy
We can reduce wasted energy to make systems more efficient.
- Lubrication - reduces friction between moving parts, so less energy is wasted to the thermal store.
- Insulation - reduces energy transfer by heating (conduction, convection), keeping heat in.
- Streamlining - reduces air resistance (drag), so less kinetic energy is wasted to the thermal store.