Flashcards in Energy Transfer Deck (16)
What is a fossil fuel?
Fuel formed from the fossilised remains of plants and animals over a long period of time.
What is renewable energy?
Wind turbines, solar panels e.t.c
Usually powered by the nuclear store of the sun
What is non- renewable energy?
Fossil fuels like coal, oil and gas.
Where can conduction occur?
Conduction only occurs in solids because particles are closer together
Metals are good conductors
How does conduction occur?
Free electrons in metal gain heat making them faster and causing them to collide with other atoms and electrons. This makes them vibrate causing heat to be passed through quicker
Where does convection occur?
In liquids and gases
How does convection occur?
1) particles gain energy and rise, becoming less dense. They become further apart and vibrate quicker
2) particles lose energy and become closer together and more dense causing them to sink
Where does radiation occur?
All objects can absorb or emit radiation
How does radiation occur?
Passes heat on as an electromagnetic wave called an infa- red radiation
It can travel through a vacum- that is how the heat from the sun reaches us
What are the advantages of using fossil fuels
- produces a lot of electricity
- can be concentrated
- can be used wherever they are needed
What are the disadvantages of using fossil fuels?
- they will eventually run out
- cause global warming
- take millions of years to replace
- create C02 when burnt
How does a power station work?
1) fossil fuels are burned heating water in the boiler producing steam
2) steam turns the turbine causing it to spin and turn the generator
3) generator produces electrical current which is transported via pylons to our homes
4) excess steam is cooled in cooling towers and the water is deposited back in the boiler
How do you calculate energy transferred?
Power (w) x time (s) = energy (j)
How do you calculate the work done?
Force (n) x distance (m) = work done (j)
What are the five energy stores?
Elastic- stretching a hair band
Gravitational potential- going up in a lift
Thermal- heating your dinner