PHYSICS · Stage 7 · Chapter 1: Energy
Physics 1.3 Energy types — Energy Stores and Pathways
5 min read 6 parts Lesson 3 of 8
Lesson summary
1.3 Energy types — Energy Stores and Pathways — Alhussan International Academy — Physics (Stages 7–9) notes: Describe the different ways energy can be stored and the ways it is transferred between stores.Common phrases — people say "heat energy", "light energy" or "electrical ene…
- Energy is a quantity
- Kinetic energy
- Chemical store
- Gravitational store
- Elastic store
- Kinetic store
Section 1 of 6Energy is a quantity, not different types
- Common phrases
- people say "heat energy", "light energy" or "electrical energy", but energy does not exist in different forms or types.
- Energy is a quantity
- it is something we calculate, and it can be stored or transferred.
- Kinetic energy
- this phrase means energy stored kinetically, or energy in a kinetic store.
- Stores
- the situation associated with each way of calculating energy is called an energy store.
- Transfers
- energy is not "transformed" from one type to another, but is transferred from one store to another.
Section 2 of 6Energy stores
| Store | Where energy is stored | Example |
|---|---|---|
| Chemical | Food, fuels and batteries | Food used to move, cook and keep warm |
| Kinetic | Moving objects | A fast car has more than a slow car |
| Gravitational potential | Objects raised above the ground | A baby lifted from the floor |
| Elastic potential | Stretched or compressed springs, bands, bows | Sofa springs, an elastic band, a catapult |
| Thermal | Hot objects, due to the movement of particles | Air heated by burning fuel |
| Nuclear | The nuclei of atoms | The Sun |
- Chemical store
- we use energy stored chemically in food and fuels to keep warm.
- Gravitational store
- when a mother lifts her baby, energy is transferred to a gravitational potential store because the position of the baby has changed.
- Elastic store
- sitting on a bed or sofa compresses the springs, so energy is stored elastically.
- Kinetic store
- all moving objects store energy kinetically.
- Thermal store
- when fuels burn, energy is transferred to the thermal store of the air, which is sometimes called "heat".
- There is more energy in the thermal store of a hot object than of a cold object.
- Change of position or shape
- a change of position or shape can store energy.
Section 3 of 6Ways energy is transferred
| Pathway | Description | Example |
|---|---|---|
| Mechanical (forces) | A force moves an object | Walking upstairs, pushing a trolley |
| Electrical | An electric current in a circuit | Battery to bulb, electric kettle |
| Heating | Energy moves from hot to cold by conduction, convection or radiation | Hot drink to air |
| Radiation (light and sound) | Waves carry energy | Sun to Earth, instrument to ear |
- Not stores
- an electric current, light, sound and forces cannot be stored, since these are the ways in which energy is transferred.
- Torch
- an electric current transfers energy from the battery to the bulb.
- Kettle
- it uses an electric current to heat water, and the energy is transferred from power stations rather than batteries.
- Light
- energy can be transferred from the Sun or a candle as light.
- Sound
- musical instruments transfer energy to your ear as sound, and vocal cords produce sound when you talk.
- Forces
- energy is transferred when forces act on objects, such as when you walk upstairs.
Section 4 of 6Energy chains
- Describing a transfer
- start with the store that decreases, name the pathway, then give the store or stores that increase.
- Torch
- the chemical store of the battery decreases, and light and the thermal store increase, by the electrical pathway.
- Climbing stairs
- the chemical store of the body decreases, the gravitational potential store of the person increases,
- and the thermal store of the surroundings also increases.
- the chemical store of the body decreases, the gravitational potential store of the person increases,
- Roller coaster climbing
- chemical energy in the motor transfers to the gravitational potential store of the car.
- Solar cell
- light from the Sun transfers energy to the electrical pathway, which charges the chemical store of a battery.
Section 5 of 6Energy from the Sun
- Radiation
- the Sun produces light and other types of radiation.
- Nuclear fusion
- it happens inside the Sun all the time, with hydrogen atoms combining to form helium and releasing energy.
- Nuclear store
- the Sun is a nuclear store of energy, and it is not a huge ball of fire.
Section 6 of 6Conservation of energy
- Conservation
- the total energy is the same before and after any transfer.
- Falling ball
- the gravitational potential store decreases and the kinetic store increases by the same amount, ignoring losses.
- Losses
- if energy seems to disappear, it has been dissipated as thermal energy in the surroundings.
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