energy transfers Flashcards
Describe the properties of heat radiation
- it travels in straight lines
- it can travel through a vacuum
- it can reflect off surfaces
- it is an electromagnetic wave much like light
- it travels at the speed of light
- it is a transverse wave
Give an example of a chemical store
battery
coal- fuel
food
Give an example of a nuclear store
Uranium in a nuclear power station
Fusion occurring in the Sun
Solids are good conductors
Liquids and gases do not conduct heat well but they do convect heat easily, why?
Liquids and gases have particles which are further apart and have weak forces between them- poor conductors
Liquid and gases have particles can move freely
Convection occurs when particles gain energy (heat up) expands and move from hot to cold regions
Why are metals good conductors of heat
Conduction occurs when heat is transferred through a material from particle to particle
Metals have free electrons which help heat transfer through the metal from particle to particle
How does heat travel from the hot stove to a potato in the water?
Conduction from the stove to the metal pan- they are in contact
Conduction through the metal pan
Conduction from the pan to the water- they are in contact
Convection to the potato- hot water expands (is less dense) and rises
Conduction through the potato
What are the disadvantages of wind power?
- you need a large area and a large number to replace one power station
- it is not reliable- no wind, no power
- they are a danger to birds on land and boats if in the sea
- they are loud and some say unsightly
Why are solids better conductors of heat than liquids and gases?
Conduction occurs when heat is transferred through a material from particle to particle
In solids, the particles are close together and the forces between particles are stronger.
What are the disadvantages of nuclear power?
- non-renewable source
- creates radioactive waste which takes thousands of years to decay to a safe level
- expensive to build, maintain and decommission
- the possibility of a meltdown causing environmental damage
What are the advantages of coal, oil or gas power stations?
they are reliable- produce a constant supply
- much of the existing infrastructure is set-up for fossil fuels
- at them moment fossil fuels are relatively cheap
What are the advantages of wind power?
- renewable energy source
- does not use fossil fuels
- does not produce carbon dioxide or other pollutants
only a small number of turbines would be needed
How is energy shifted/transferred from the power station usefully and wastefully?
Usefully- Electrically via wires
Wastefully- Heating from furnace, wires and cooling towers
Radiated as sound from generator
Radiated as light from furnace
Give an example of a kinetic store
car, moving
spaceship, moving
bullet moving
generator turning
The fleece reduce heat loss in two ways? Explain
The fleece traps air
air is a poor conductor- reduces heat loss by conduction
air cannot move- no convection currents set up- reduces heat loss by convection
What are the disadvantages of a hydroelectric power station?
- flooding of valleys and loss of habitats
- can only be built in areas which are mountainous.
- flooding of valleys and displacement of communities
- expensive to build
How does energy transfer or shift from the chemical store of a battery to the thermal store of a bulb?
Electrically- charge moves in wires
Which container will heat up the quickest?(colours)
The matt black container
Matt black surfaces are good absorbers of heat radiation
Shiny silvery surfaces will reflect heat radiation
Give an example of a thermal store
hot pan
hot water in a kettle
the filament in a toaster
a human body
What are the 8 stores of energy?
Chemical
Thermal
Gravitational
Kinetic
Vibrational
Nuclear
Electrostatic & magnetic
Elastic
How does energy transfer or shift from a stretched elastic in a catapult to moving stone?
mechanically- elastic exerts a force on the stone
Elastic store of elastic is emptied
Kinetic store of stone is filled
How is energy wastefully shifted/transferred from the wind turbine
Energy is wastefully shifted/transferred from the wind turbine via radiation (sound) and heating from wires and generato
What energy store does biomass possess?
Chemical store
Give an example of electrostatic & magnetic energy store
one of each!
Electrostatic
Two similarly charged particles near each other
Charged van de Graaf generator
Magnetic
North and north pole of a magnet pushed together
North pole of a magnet and south pole of an electromagnet pulling in a speaker cone
advantage of nucleus power
Produces no polluting gases.
Does not contribute to global warming.
Very low fuel costs.
Power station has very long lifetime.
advantage of geothermal
advantages MP13.consistent/reliable power
output;
MP14. does not take up a lot of land space;
disadvantage of geothermal
can only be built in
geologically active areas/owtte;
advantages of solar panels
MP3.can be put on existing
buildings
disadvantage of solar panels
only generates electricity when it is sunny / eq;
MP5.would require a large area of panels;
MP6.idea of visual pollution;
advantages of any renewable resources
MP1.resource will not run out; MP2.no polluting gases produced;
describe the process of the air movement convention
air is heated by fire molecules speed up and gain ke they spread out air becomes less dense it rises it is replaced by cold denser air the air above cools down, becomes denser and sinks there is a convection current
how vacuum flask reduces heat transfers
plastic is a bad conductor
prevents convection to the outside
vacuum has no particles so no conduction or convection
silver surfaces are good at reflecting heat
