Energy Flashcards
What are the 8 stores of energy?
- Gravitational potential energy store
- Chemical energy store
- Kinetic energy store
- Elastic potential energy store
- Magnetic energy store
- Electrostatic energy store
- Thermal energy store
- Nuclear energy store
What store of energy is found in food, batteries and fuels?
Chemical energy store
An ambulance is travelling at 70kph to reach an emergency. It has energy in it’s __________ energy store.
Kinetic
A stretched elastic band has energy in it’s _________ energy store
Elastic
Two magnets that attract or repel each other have energy in their _________ energy stores.
Magnetic
Everything has some energy in its _________ energy store.
Thermal
A ball at the top of a hill has energy in its ____________ energy store.
Gravitational potential
Energy can be transferred between energy stores. What are the 4 pathways through which energy can be transferred?
- Mechanical pathway
- By heating
- Electrically
- By radiation
When is energy transferred mechanically?
When a force makes something move. E.g. if an object is pushed, pulled, stretched or squashed.
What is energy transferred by heating?
When energy is transferred from a hotter object to a colder object.
When is energy transferred electrically?
When electrical charges move around an electric circuit due to a potential difference.
When is energy transferred by radiation?
When light or sound waves carry energy from one place to another.
Explain why an ice-pop melts if left on a kitchen table?
When there is a temperature difference between two objects energy will be transferred from the thermal store of the hotter object to the thermal store of the colder object.
This continues until both object reach the same temperature.
Describe how energy is transferred by conduction.
When an object is heated its particles gain energy in their kinetic stores. They start to vibrate more and bump into neighbouring particles. In this way the energy is transferred.
Define radiation in terms of energy transfer.
Radiation is the transfer of energy by waves (not particles). The energy from the sun reaches the earth by radiation.
What type of object emit or absorb radiation?
All objects emit (give out) radiation and object absorb radiation too.
Some objects are better or worse at emitting or absorbing radiation.
How is radiation different to conduction and convection?
It transfers energy by waves, NOT particles.
What type of surfaces are better absorbers and emitters of infrared radiation?
Matt dark surfaces are better absorbers and emitters of infrared radiation than shiny light surfaces.
Which words would fit best for the blanks below:
White (or silver) and shiny surfaces do not _________radiation well and _________ radiation instead of absorbing it.
White (or silver) and shiny surfaces do not emit radiation well and reflect radiation instead of absorbing it.
State the principle of conservation of energy.
Energy can not be created nor destroyed, it can only be transferred from one energy store to another.
Right now we generate most of our electricity by burning _______ _________.
Fossil fuels
What are renewable energy resources?
Renewable energy resources are resources that are being used up at the same rate as they can be replaced.
Give some examples of renewable energy resources.
- Sun (solar energy)
- Water (tidal energy)
- Wind
- Biomass
- Hydroelectric
- Geothermal
What is meant by a ‘non renewable’ energy resource?
Non-renewableenergy resources cannot be replaced once they are all used up.
What are the 4 forms of non-renewable energy resources.
- Coal
- Oil
- Gas
- Nuclear
Name the 3 fossil fuels that are non-renewable energy resources.
Coal, Oil, Gas are all fossil fuels.
Which word means ‘there is a limited amount’ in terms of energy resources.
Finite
Give 2 examples of non-renewable nuclear fuels.
- Uranium
- Plutonium
Which energy store is in fossil fuels?
Chemical energy store
Name 2 ways we could reduce the amount of fossil fuels we use.
- Save energy (turn off lights, drive electric cars etc).
- Recycle
- Use more renewable energy
What is an ‘electrical appliance’?
Anything that required electricity to work. E.g. a television.
What does ‘power’ tell us?
How fast an appliance transfers energy.
What are the units of power?
Watts (W) or kilowatts (kW).
1kW = ? W
1kW = 1000 W
What does the total amount of energy transferred by an appliance depend on?
The total amount of energy transferred by an appliance depends on how long it is running for (time) and it’s power.
What is the formula to calculate energy transferred by an electrical appliance?
Energy transferred (J) = Power (W) x time (s)
A 2000W kettle boils in 150 seconds. Use the formula to calculate the energy transferred.
Energy transferred (J) = Power (W) x time (s)
= 2000W x 150 s
= 300,000 J
