energy resources and energy transfers 4 Flashcards
what are the 8 energy stores?
chemical
kinetic
gravitational
elastic
thermal
magnetic
electrostatic
nuclear
what are the 4 energy transfers?
mechanically via a force
radiation via a light or sound
electrically via a motion of charge
heating via hot to cold
what energy stores and transfers do a torch use?
- chemical store of a battery depletes
- energy is transferred electrically through wires
- thermal store is filled
- energy to surrounds by heating and radiation
what energy stores and transfers does a blender use?
- electrically through wires
- kinetic store via the blending and thermal store of blades
- liquid is mechanically heated and radiation (sound)
what energy stores and transfers does a catapult use?
- elastic store of the rubber bands depleted
- transferred mechanically to kinetic store of rock via the elastic force
what energy stores and transfers does a microphone use?
- to microphone by radiation (sound)
- from microphone electrically through wires
what energy stores and transfers does a light bulb use?
- transferred to light bulb electrically through wires
- thermal store of filament increases
- from the filament useful energy of radiation and wasteful energy by heating
what energy stores and transfers does a match use?
- chemical store of match depleted
- thermal store is filled
- energy transfers via heating and radiation
what’s the law of conservation of energy?
energy cannot be created or destroyed only transferred from one store to another
what are the energy transfers of coal, oil, and gas electricity?
- chemical store of fuel depleted
- thermal store of water filled up
- kinetic store of water filled up
- energy transferred to turbines mechanically via steam on turbine blades
- kinetic store of turbines filled
- energy transferred to generator mechanically
- kinetic store of generator filled
- energy is transferred electrically from the generators via wires
what are the advantages and disadvantages of coal, oil and gas electricity?
reliable-constant source of power
releases lots of energy
cheap
non-renewable
produces CO2 which is a green house gas
produces sulfur dioxide and nitrous oxides which creates acid rain
whats the energy transfers involved with nuclear electricity?
- nuclear store of uranium is depleted
- thermal store of water filled up
- kinetic store of water filled up
- energy transferred to turbines mechanically via steam on turbine blades
- kinetic store of turbines filled
- energy transferred to generator mechanically
- kinetic store of generator filled
- energy is transferred electrically from the generators via wires
whats the advantages and disadvantages of nuclear electricity?
reliable-constant source of power
doesn’t produce CO2
doesn’t produce sulphur dioxide or acid rain
small amount of fuel = lots of energy
non-renewable
radioactive waste that takes years to drop to a safe level
possibility of major meltdown = catastrophic effect on environment
expensive
whats the energy transfers of wind?
- kinetic store of wind is depleted
- energy is transferred to the blades mechanically via the force of wind on the blades
- kinetic store of blades is filled
- energy is transferred mechanically to the generator
- kinetic store of generator is filled
- energy is transferred electrically from the generator via the wires
whats the advantages and disadvantages of wind electricity?
cheap to run, wind is free
doesn’t use fossil fuels
renewable source
doesn’t contribute to global warming
doesn’t create acid rain
not a reliable source - no wind, no power
spoil view
large number needed to replace one coal power station
danger to wildlife - birds etc
noisy
expensive to set up (especially at sea)
whats the advantages and disadvantages of hydroelectric electricity?
cheap to run - no fuel
no problem of reliability (except drought)
doesn’t use fossil fuels
renewable energy source
doesn’t produce carbon dioxide
doest produce sulphur dioxide
initially expensive to build
loss of habitat
towns or villages may have to be relocated
fish spawning routes are disrupted
only built in mountainous areas
whats the advantages and disadvantages of wave electricity?
cheap to run
renewable energy source
doesn’t contribute to global warming
doesn’t create acid rain
initially expensive to build
not reliable - no wind, no power
large number needed
danger to boats and ships
spoil view
whats the advantages and disadvantages of tidal wave electricity?
cheap to run - no fuel
reliable
doesn’t contribute to global warming
initially expensive to build
alters fish habitats
can only be built if there is an estuary
whats the advantages of geothermal electricity?
cheap to run
reliable
doesn’t contribute to global warming or damage of the enviroment
whats the energy transfers of solar cells electricity?
nuclear store of sun depleted
energy is transferred from the sun as radiation (light)
solar cells absorb light radiation
energy is transferred electrically via the solar cell wires
whats the advantages and disadvantages of solar cells?
cheap to run
doesn’t affect environment and global warming
initially expensive to build
not reliable - cloudy, less power
unsightly
what is the transfer of energy the same as?
power
the rate of doing work
what’s the equation for power?
power = work done / time taken
whats power measured in?
watts W
what does one watt mean?
one joule of work done per second
what is the relationship of efficiency, useful energy output and total energy output?
efficiency = useful energy output/total energy output
what is conduction?
the transfer of heat energy through solid matter from particle to particle
the material MUST be in contact
hot end of metal is heated
particles at the heated end start vibrating more (they are gaining energy)
these particles vibrate and pass the energy to adjacent particles via collisions
this allows energy to pass from particle to particle throughout a material
matter must be in contact in order for particles to collide with one another
what helps conduction?
metals are good conducts - they have free electrons which help in the process of conduction
solids are good conductors - the particles are close together and they have strong forces between them
what hinders conduction?
insulators - such as plastic and wood - as they don’t conduct heat well, they have no free electrons
liquid and gases are not conducts as their particles are far apart making the collision between particles more difficult
what is convection?
the transfer of heat energy through heated fluid by movement of particles from hot to cold (gas or liquid)
hot object heats the air above it
the particles in the air vibrate more
making the air particles spread out and become less dense
the less dense air rises
the denser cool air places hot hair b
as the hot air cools it falls and a convention current is set up
what helps convection?
convection only takes place in builds as particles carry energy with them from hot regions to cold regions so having space and no restriction is important for convection currents to be set up
what hinders convection?
restricting the movement of particles by adding foam stops convection currents as the air is redistricted in the pockets of air in the foam
a vacuum means no particles are there to convect the heat
what is radiation?
transfer of heat by electromagnetic radiation of infrared radiation
all hot objects radiate heat
the radiation is in the form of electromagnetic waves
they travel in straight lines and they can be reflected and can travel through a vacuum
what helps radiation?
matt black objects radiate heat well
high surface areas allow for more heat to be radiated
hotter objects radiate heat more rapidly
what hinders radiation?
shiny silvery surfaces stop heat loss by radiation as the surface colour and texture help reflect the heat back in
low surface area reduces the amount of heat radiated from hot object
matt black is a good…
radiator and absorber
shiny silver is a poor…
radiator and absorber
investigating thermal energy transfer by conduction:
independant variable - type of metal
dependant variable - time for pin to fall off
control variables - thickness of metal rod
length of metal rod
position of pins
temp of water
initial temperature of rods
room temperature
results - the metal with the smallest time will be the best conductor of heat
investigating thermal energy transfer by convection:
independant variable - container with lid, container without lid
dependant variable - temperature drop after 20 minutes
control variables - volume of water
initial temperature of water
type of thermometer
room temp
results - the container with the lowest temperature drop loses the least amount of heat via convection
investigating thermal energy transfer by radiation:
independant variable - colour and texture of the block
dependant variable - temperature difference after 15 minutes
control variables - size of metal block
initial temperature of block
type of thermometer
results - the greatest temperature difference indicates that the object is a better absorber of radiation
how does loft insulation reduce unwanted energy transfer?
stops heat loss by conduction and convection
it is made of glass which is an insulator and has air pockets
air is a poor conductor
pockets of air prevent convection currents being set up
how does double glazing reduce unwanted energy transfer?
stops heat loss by conduction and convection
the vacuum between the panes of glass means there is no particles to transfer the heat via collisons / conduction or convection currents
how does shiny foil behind radiators reduce unwanted energy transfer?
foil is silvery in colour and shiny in texture
this prevents heat loss by radiation
the heat radiating from the radiator is reflected back into the room
what’s the energy transfers of hydroelectric power?
- gravitational store of the water behind the dam is depleted as it flows down the tunnels from the top of the dam
- energy is transferred to the water mechanically via the gravitational force
- kinetic store of water is filled
- energy transferred to generator mechanically
- kinetic store of generator filled
- energy is transferred electrically from the generators via wires
whats the energy transfers in wave electricity?
- kinetic store of water is depleted
- energy is transferred to wave buoy mechanically via a force upward on the buoy by the water
- gravitational store of buoy is filled
- energy transferred to generator mechanically
- kinetic store of generator filled
- energy is transferred electrically from the generators via wires
whats the energy transfers in tidal power?
- gravitational store of the water on one side of the tidal barrage is depleted as it flows through the tunnels
- energy is transferred to the water mechanically via the gravitational force
- kinetic store of water is filled
- energy transferred to turbines mechanically via steam on turbine blades
- kinetic store of turbines filled
- energy transferred to generator mechanically
- kinetic store of generator filled
- energy is transferred electrically from the generators via wires
what are the energy transfers of geothermal power?
- thermal store and nuclear store of earth’s core is depleted
- energy is transferred via heating the water
- thermal store of the water is filled
- kinetic store of water is filled
- energy transferred to turbines mechanically via steam on turbine blades
- kinetic store of turbines filled
- energy transferred to generator mechanically
- kinetic store of generator filled
- energy is transferred electrically from the generators via wires
what’s the realtionship between gravitational potential, mass, gravity and height?
gravitational potential energy = mass x gravitational field strength x height
what’s the relationship between kinetic energy, mass and speed?
kinetic energy = 1/2 x mass x speed2 (squared)
what’s the equation for power?
power = work done / time taken
