energy Flashcards
What is a system?
An object or a group of objects.
What is a closed system?
A system where no energy can escape to, or enter from, the surroundings and the total energy never changes.
What is kinetic energy?
The energy an object has because of its movement.
What is gravitational potential energy?
The energy an object has because of its height above the ground.
What is elastic potential energy?
Energy an elastic object has when it is stretched or compressed.
What is thermal/internal energy?
Energy an object has because of its temperature.
What is the equation for thermal/internal energy?
Internal = Kinetic + potential energy
What is chemical energy?
Energy that can be transferred by chemical reactions involving foods, fuels and chemicals in batteries.
What is nuclear energy?
Energy stored in the nucleus of an atom.
What is magnetic energy?
Energy a magnetic object has when it is near a magnet or in a magnetic field.
What is electrostatic energy?
Energy a charged object has when it is near another charged object.
What are the 8 energy stores?
Kinetic, gravitational potential, elastic potential, thermal/internal, chemical, nuclear, magnetic, electrostatic.
In what ways can energy be transferred?
By heating, waves, electricity and forces.
How can energy be transferred through heating?
Energy transferred from one object to another with a lower temperature.
How can energy be transferred through waves?
By radiation.
How can energy be transferred through electricity?
When an electric current flows it can transfer energy.
How can energy be transferred through forces?
Energy transferred when a force moves or changes the shape of an object.
Factors that affect the rate of heat loss from a building:
- The thickness of its walls and roof.
- The thermal conductivity of its walls and roof.
What are thermal insulators?
A material which has a low thermal conductivity and the rate of energy transfer is low.
How can your reduce thermal conductivity?
By using thermal insulators.
What does the energy transfer through a material depend upon?
- The material’s thermal conductivity.
- The temperature difference between the 2 sides of the material.
- The thickness of the material.
What is the conservation of energy?
Energy cannot be created or destroyed, only transferred usefully, stored or dissipated.
Define lubrication.
A way of reducing unwanted energy transfer due to friction.
Define streamlining.
A way of reducing energy wasted due to air resistance or drag in water.
What does all energy end up being transferred to?
The thermal energy store of the surroundings.
What are examples of energy transfers?
Light, sound, thermal, chemical, mechanical, electrical.
What are the 3 fossil fuels?
Coal, oil and natural gas.
What are the advantages of the fossil fuels?
- Reliable.
- Cheap to extract and use.
What are the disadvantages of fossil fuels?
- Non-renewable.
- Release carbon dioxide , cause of global warming.
- Will eventually run out.
What are the disadvantages of using nuclear energy?
- Non-renewable.
- will eventually run out.
- Produces radioactive waste (dangerous, difficult and expensive to dispose of ).
- Expensive to comission and decomission (shut down) power stations.
What are the advantages of using nuclear energy?
-No polluting gases or greenhouse gases produced.
-Reliable.
Doesn’t cause acid rain.
What are the advantages of using solar energy?
- Renewable.
- Cheap to run once installed.
- No pollution/greenhouse gases produced.
- Can be used in remote places.
What are the disadvantages of using solar power?
- Unreliable.
- Supply depends on weather.
- Expensive to buy and install.
- Cannot supply large scale demand.
What are the advantages of using hydroelectric energy?
- Renewable.
- Low running cost.
- Reliable.
- No fuel cost.
What are the disadvantages of hydroelectric energy?
- Expensive to build hydroelectric energy.
- Destroys habitats.
- Greenhouse gases produced because of rotting vegetation.
What are the advantages of tidal energy?
- Predictable.
- Can produce large amounts of energy.
- No fuel costs.
- no pollution/greenhouse gases produced.
What are the disadvantages of tidal energy?
- Expensive to build and maintain.
- Can change aquatic habitats and harm animals.
- Restrict access and dangerous for boats.
- Inconsistent.
What are the advantages of wave energy?
- Low running cost.
- No fuel cost.
- No polluting/greenhouse gases produced.
What are the disadvantages of wave energy?
- Unreliable.
- Dependant on weather.
- Floating generators can change aquatic habitats and harm animals, restrict access and dangerous for boats.
- Floating generators expensive to build, install and maintain.
What are the advantages of wind energy?
-Low running cost.
-No fuel cost.
No polluting/greenhouse gases produced.
What are the disadvantages of wind energy?
- Unreliable.
- Supply depends on weather.
- Large amounts of land needed to produce enough electricity for large scale demand.
- Noise and visual pollution.
What are the advantages of using geothermal energy?
- Low running cost.
- No fuel cost.
- No polluting/greenhouse gases produced.
What are the disadvantages of geothermal energy?
- Expensive to set up.
- Only few suitable locations.
What are the advantages of biofuels?
- Reliable.
- Carbon neutral.
What are the disadvantages of biofuels?
- Expensive to produce.
- Requires land and water that’s useful for food production.
What does non-renewable mean?
- Energy resources are not replaced as quickly as they are used.
- Will eventually run out.
What does renewable mean?
- Energy resources can be replaced at the same rate as they are used.
- Will not run out.
What are examples of non-renewable energy resources?
Fossil fuels and nuclear fission.
What are examples of renewable energy resources?
Solar, tidal, wave, wind, geothermal, biofuel and hydroelectric energies.
What is power?
How much energy/work done is transferred per second.
