energy Flashcards
what is internal energy
the sum (total) of the kinetic energy and potential energy stored in the object’s particles.
what is temperature
a measure of the energy in the kinetic stores of its particles.
what happens if you increase the bodies temp
increases the energy in the kinetic stores of the body’s particles, which means that the energy in the body’s internal store also increases.
unit of mass
kilograms
unit of velocity
meters per second
unit of energy
joules
unit of spring constant
Newtons per meter
unit of extension
meters
what are the 4 energy transfers
electrical
mechanical
wave
heating
what is the work done by a force
energy transferred to the object
in what ways is more work done
push with the same force for a longer distance.
push with a larger force for the same distance.
units of work done
joules
units of force
newtons
units of distance
meters
what is electrical work
work done when a current flows
WEQ = electrical work
energy = potential difference x current x time
unit of time
seconds
what is power
the rate of energy transfer
unit of power
watt
what is wasted energy
transferred into unwanted stores of energy
what does wasted energy do
dissipates
what are examples of wasted energy
heat and sound
what can efficiency never be
more than 100
how to reduce unwanted energy transfer in walls
Having thicker walls.
Having walls made from a material with a lower thermal conductivity.
uses of insulation
Fit loft insulation (the roof).
Use double glazing (windows).
Use cavity wall insulation (walls).
Fit carpets (floors).
main ways to reduce energy transfer
insulation and lubrication
why does lubrication reduce energy transfer
reduces friction
what is power
energy transferred per second
the higher the thermal conductivity
the higher the rate of energy transfer by conduction across the material
how does the mass affect the GPE
increasing the mass increases the GPE
what is an energy resource
used to generate electricity and other useful forms of energy
steps to generate and transfer electricity
an energy resource is used to rotate a turbine.
The rotating turbine rotates a coil of wire in a magnetic field
this creates an electric current
advantages of fossil fuels
reliable
disadvantages of fossil fuels
Not renewable.
Inefficient.
Contributes to global warming
advantages of geothermal
Renewable.
Reliable.
Does not produce greenhouse gases.
disadvantages of geothermal
only used where there is volcanic activity
can lead to ground instability
advantages of wind power
renewable energy.
don’t take up much land space.
Relatively low cost.
disadvantages of wind power
Unreliable
ugly or an eyesore.
cause noise pollution.
advantages of hydroelectric power
Renewable.
More reliable than wind and solar.
Capable of producing lots of energy.
disadvantages of hydroelectric power
change paths of rivers
harm local wildlife
advantages of tidal power
Renewable source of energy.
Does not produce greenhouse gases.
Tides are a predictable phenomenon.
disadvantages of tidal power
damage fragile ecosystems
isnt continuous
advantages of nuclear energy
No greenhouse gas emission
Reliable, on-demand electricity.
disadvantages of nuclear energy
radioactive and needs to be disposed of property
advantages of solar energy
Renewable.
Produces no greenhouse gases.
Produces no noise pollution
disadvantages of solar energy
unreliable
High cost of installation.
not very efficient at converting sunlight into energy.
what are two main resources of energy
transport
heat
why has electricity use been decreasing in the UK
appliances are becoming more efficient
more concerned
why has the way we use energy resources changed overtime
environmental concerns
changing costs
tech advances
what are changes to make things more renewable
government policy
vehicles
power plants
what factors limit the use of renewable energy
reliability
cost
charity
