ENERGY RESOURCES AND TRANSFERS Flashcards
energy stores:
- chemical
- kinetic
- gravitational
- elastic
- thermal
- magnetic
- electrostatic
- nuclear
energy transfers:
- mechanically
- electrically
- by heating
- by radiation (light and sound)
what is the principle of conservation of energy?
energy cannot be created or destroyed, only transferred from one store to another
relationship between efficiency, useful energy output and total energy output:
efficiency= useful energy output/ total energy output x 100
what is conduction?
The transfer of heat energy through the vibrations of particles in a medium
what is convection?
The transfer of heat energy through convection currents in a fluid
what is radiation?
The transfer of energy, without the transfer of matter. No medium is needed for radiation to occur
role of convection in everyday phenomena:
- distributing heat energy
- such as in a radiator
what are matte black surfaces good at?
poor reflectors and good at absorbing IR
what are shiny silver surfaces good at?
good reflectors of IR and so are poor at absorbing it
ways of reducing unwanted energy transfer:
- insulation
- air
- foam
- feathers
relationship between work done, force and distance moved:
work done= force x distance moved
work done is equal to….
energy transferred
relationship between gravitational potential energy, mass, gravitational field strength and height:
gravitational potential energy= mass x gravitational field strength. x height
how to work out kinetic energy:
1/2 x mass x speed ^2
what does conservation of energy produce a link between?
- gravitational potential energy, kinetic energy and work
- because energy is conserved the decrease in GPE = increase in KE, for a falling object if no energy is lost to the surroundings
what is power?
- rate of transfer of energy or the rate of doing work
relationship between power, work done and time taken:
power= work done/ time taken
P2 energy transfers involved when there is a turbine (wind and hydroelectric):
energy in the KINETIC STORE of the flowing water is transferred to the KINETIC STORE of the turbine and then to the KINETIC STORE of the generator and transferred ELECTRICALLY to the National Grid
P2 energy transfers involved when a fossil fuel is combusted into steam:
Energy from the CHEMICAL STORE of the fuel is transferred to the THERMAL STORE of the water, which is then transferred to the KINETIC STORE of the turbine, and then transferred to the KINETIC STORE of the generator and then transferred ELECTRICALLY to the National Grid
P2 ADVANTAGES of wind:
- renewable
- doesn’t produce any greenhouse gases
P2 DISADVANTAGES of wind:
- weather dependent
- can be noisy
- eye saw
P2 ADVANTAGES of hydroelectric:
- renewable
- minimal running costs
P2 DISADVANTAGES of hydroelectric:
- ruin the view
- hazardous to boats
- unreliable
P2 ADVANTAGES of solar cells:
- renewable
P2 DISADVANTAGES of solar cells:
- require lots of land
- unreliable
P2 ADVANTAGES of nuclear:
- renewable
- reliable
P2 DISADVANTAGES of nuclear:
- produces dangerous radioactive waste
P2 ADVANTAGES of fossil fuels:
- reliable
- can produce a large amount of energy in a small time
P2 DISADVANTAGES of fossil fuels:
- produce CO2
- pollute the atmosphere
P2 ADVANTAGES of biomass:
- the CO2 produced is the same as the CO2 absorbed
P2 DISADVANTAGES of biomass:
- can take up lots of land
