conservation of energy - topic 2 Flashcards
what is kinetic energy
anything moving has kinetic energy
what is thermal energy
any object but the hotter it is the more thermal energy it has
what is chemical energy
anything that can release energy by a chemical reaction, such as energy stored in batteries
what is gravitational potential energy
Height
what is elastic potential energy
anything that is stretched or compressed
what is electrostatic energy
anything with electric charge that is interacting with another electric charge
what it magnetic energy
anything magnetic that is interacting with another magnet
what are the 4 ways energy can be transferred between stores
mechanically, be heating , electrically and by radiation
mechanical
pushing and pulling
what is electrical energy
charges moving around a circuit
what is work done
way of saying energy transferred
what is the conservation of energy principle
energy can be transferred usefully, stored or dissipated but never created or dissipated
what is the equation for total energy input
useful energy output + wasted energy
what is the equation for kinetic energy
1/2 x mass x velocity^2
what is the equation for change in GPE
mass x gravitational field strength x change in vertical height
how to reduce amount of energy lost from buildings using thermal insulators
cavity walls
double glazing
loft insulation
hot water tank jacket
what are lubricants used for
reducing friction between two surfaces when the move
what is the equation for efficiency
useful energy transferred / total energy transferred
what are the 4 non renewable energy sources
coal
oil
natural gas
nuclear fuels
what are the 5 renewable energy sources
wind tides sun hydroelectricity bio-fuel
uses of petrol
powers lots of vehicles
uses of coal
heating, old fashioned steam trains
uses of oil
heating homes
uses of natural gas
radiators which are used for heating homes
pros of wind power
no pollution
cons of wind power
very noisy
high initial cost
not reliable
spoil the view
pros of solar cells
no pollution
reliable in very sunny countries
cons of solar cells
high initial costs
need a lot energy to manufacture
only generate electricity during the day and not at night
pros of hydro-electricity power stations
no pollution
reliable except in a drought
provide immediate response to increasing demand for electricity
cons of hydro-electricity power stations
flooding
habitats destroyed
vegetation destroyed
high initial costs
pros of tidal barrages
no pollution
reliable
cons of tidal barrages
spoil the view
alter habitat of wildlife
high initial cost
pros of bio-fuel
reliable
carbon neutral
cons of bio-fuel
high refinery costs
produce carbon dioxide when burned
take up space for growing crops
takes long to grow crops
how do cavity walls and double glazing remove unwanted energy transfers
they both an inner and outer wall/ sheets of glass with an air gap in the middle which reduces the amount of energy transferred by conduction through walls or windows
how can you improve efficiency
decreasing amount of wasted energy and making sure more of the supplied energy goes to the useful stores by lubrication or thermal insulation
how does wind generate electricity
a wind turbine has a generator inside it which generates electricity when wind turns the blades which turns the generator
how does the sun generate electricity
solar cells generate electric currents directly from the sun’s radiation and so can be used to charge batteries that can power electrical devices
how do bio-fuels generate electricity
they are burned to heat water, which produces steam which drives a turbine, which drives a generator and generates electricity
