energy stored in food, fuel and batteries

energy stored in stretched, squashed or twisted materials 

energy stored in objects in high positions 

energy cannot be created or destroyed, it can only be transferred between different stores of energy 

total energy transferred by a system is equal to 

shows amount of energy transferred represented by the width of arrows 

gets dissipated (spread out) into the surroundings

lubrication such as gasses, oil or other liquids 

how can friction between moving parts be reduced?

how good a machine is at transferring energy into useful forms 

useful energy transferred by device          —————————————————          total energy supplied to device 

slows down the rate at which energy is transferred out of a house by heating 

vibrations are passed on between particles in a solid 

metals                                                  (wood is a poor conductor but a good thermal insulator)

what is an example of a good thermal conductor?

the part of a fluid that is warmer than the rest rises and sets up a convection current

the only way energy can be transferred through a vacuum

can pass through gases and some solid materials                                                       is absorbed and emitted easily by dull, dark surfaces and is absorbed and emitted poorly by light, shiny surfaces  

a measure of how easily energy can pass through a material by heating

if a material has low thermal conductivity…

why are materials that contain air good thermal insulators?

 it cannot form convection currents and so does not transfer much energy 

it depends on its thickness, thermal conductivity and temperature difference across it

what does the rate of energy transfer through a material by heating depend on?

it can be reduced by increasing thickness, decreasing thermal conductivity and decreasing temperature difference 

how can the rate of energy transfer be reduced?

it depends on the mass of the object, strength of gravity and how far the object is moved upwards 

what does the amount of GPE stored depend on?

what does the amount of kinetic energy stored in a moving object depend on?

they store a lot of energy in a small piece of material 

why are nuclear fuels like uranium useful for space craft

nuclear fuels or fossil fuels - non renewable

they emit less CO2 (cause less pollution) and produce the same amount of energy 

why are natural gas power stations better than fossil fuelled power stations?

they don’t emit CO2 or other gases but produce radioactive waste that stay radioactive for years and are expensive to dispose safely and decommission (dismantle safely) nuclear power stations at the end of its life 

does it cost more to build and decommission nuclear power stations or a fossil fuelled one?

convert solar energy into electrical energy in solar farms, house roof tops or power stations (not available all the time)

generated by falling water in places where water can be trapped in high reservoirs (available as long as reservoir does not dry up) and can be started and stopped quickly unlike fossil fuel power stations 

generated as long as the wind speed is not too slow or fast

a lot is needed to produce the same amount of energy as a fossil fuelled power station  

generated when turbines in a huge dam across a river estuary turn as tides flow in and out (not available all the time but at predictable times)

there are not many places suitable for barrages and affect wildlife that live or feed on tidal mudflats

made from animal wastes, plants or waste wood and can be used in the same way as fossil fuels 

they release the same amounts of CO2 when burnt as they took when the plants grew

energy is also needed to grow and harvest crops to turn them into fuel

why are biofuels considered to not really be carbon-neutral?

what are other ways electricity can be generated?

it is not available all the time and takes lot of land to obtain energy from bio fuels or other resources 

Physics P3 (combined)

Flashcards

Forces - GCSE physics

AQA GCSE PHYSICS TOPIC 4 - atomic structure - FLASHCARDS

[Seperate] Physics Topic 8: Space & other (MASTER Booklet)

Physics P3 (combined)

Flashcards

Forces - GCSE physics

AQA GCSE PHYSICS TOPIC 4 - atomic structure - FLASHCARDS

[Seperate] Physics Topic 8: Space & other (MASTER Booklet)