Studied by 1 personwhat is the mnemonic to remember the energy stores
geeks lunch, u doesnt stand for anything
what are the 9 energy stores
gravitational potential, electrical, elastic potential, kinetic, sound, light, nuclear, chemical, heat/thermal energy
system
group of objects, when it changes there are changes in the way energy is stored
closed system
a system that has no changes in the energy stores the energy is being transferred between
what is the law regarding conservation of energy
energy cannot be created or destroyed it can only be moved/ transferred into another type of energy
where can energy go during an energy transfer
transfer or dissipate
what do we say energy transferred is
work done
what does work done depend on
the amount of force applied in newtons and how much it has moved an object along a line
what is work done measured in
joules
when work is done to overcome friction, what store does the energy change into
thermal
friction in humans
rub your hands together= heat
gravitational potential energy
energy store that shows the position of an object in relation to its elevation and mass
what is gravitational potential energy measured in
joules
kinetic energy
energy an object has because of its motion
what is kinetic energy measured in
joules
elastic potential energy
the work done on an elasticated object
what is elastic potential energy measured in
joules
when energy dissipates, what two categories does it go in
useful energy, wasted energy
useful energy
energy transferred to where its wanted in the way that its wanted
wasted energy
energy that is not transferred where its wanted
efficiency
how well and object uses its energy and doesnt waste it
how to improve efficiency
lubricate parts to prevent friction (thermal energy)
streamline shapes of moving objects to reduce air resistance
tighten loose parts to prevent sound energy
power
the amount of energy supplied to an object per second
what is power measured in
watts or kilowatts
how many watts in a kilowatt
1000
thermal conductivity
how well a material is able to conduct heat
why is insulation thick
to reduce thermal conductivity and prevent heat escaping
how can we detect heat coming off a building
using an infared camera- red means lots of heat so its escaping and blue means cold so heat is not escaping
specific heat capacity
the amount of energy 1kg of an object needs to raise its temperature by 1 degree celcius
what is the specific heat capacity measured in
j/kg°C
renewable energy
energy that wont run out and we can get more
biofuel
fuel taken from living or recently living organisms e.g animal dung, ethanol from sugarcane
nuclear fuel
fuel derived from unstable nuclei of atoms splitting and transferring energy (thermal)
name 4 renewable energy resources
sun/ heat (solar panels), wind (turbines), water (tidal, hydroelectric power, waves), geothermal
solar energy definition + pros and cons
panels absorbing suns rays making them into energy
renewable and doesnt emmit co2
depends on light intensity, doesnt happen at night, very expensive
wind energy definition + pros and cons
wind spins turbines spinning motor to produce energy
efficient and renewable
eyesore, danger to birds, doesnt provide constant source of energy
wave energy definition + pros and cons
waves push a floating generator up and down which drives an internal generator to generate electricity
renewable
expensive and cables across coast are an eyesore
hydroelectric power definition + pros and cons
rainwater that is collected flows down and turns a generator as it flows
renewable
required flooding which displaces people and infrastructure
tidal energy definition + pros and cons
as tides go up and down they spin turbines underwater converting the spinning into energy
renewable variations in tide affect output, can alter habitats and be a nuisance for shipping overseas
geothermal energy definition + pros and cons
steam from hot rocks rotates turbine
renewable
eyesore, only available in small number of areas where hot rocks are close to surface
finite energy/ non renewable energy
energy that will run out, usually produces global warming
name the 2 types of non-renewable energy
nuclear fuel, fossil fuels- coal, oil, gas
fossil fuels definition + pros and cons
dug up from crust and made over millions of years, burnt to generate power
effective
polluting, not infinite so close to running out, expensive to extract, contributes to acid rain, climate change
nuclear power definition + pros and cons
nuclear energy outputs power from a very high concentration to a lower amount
effective and produces a lot
very dangerous, waste has to be stored for long periods of time
Note
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