Energy Flashcards
When a metal bar is heated at one end, the free electrons at that end … They … And … With other free electrons. As a result, they … Energy from the hot end of the metal. The free electrons … With the atoms and make them … More.
Move faster Vibrate Collide Transfer Collide Diffuse
Metals are good conductors because…
They contain lots of electrons that can move about freely inside the metal
What material is the best conductor
Copper
What material is used to make saucepan handles from
Plastic
Which material would be best for loft insulation
Felt/foam
Which material is used to make heating radiators from
Steel
Ways to reduce heat loss from your home
Double glazed windows
Loft insulation
Thermostat
Double glazed windows
Vacuum in the middle of two glass panes with a plastic frame
Double glazed windows cut down heat loss in the house as glass is a … Conductor and the panes are … Times as thick as a single pane. Plastic is a … Insulator so it … Very little heat. There is no … Or … Through the vacuum because a vacuum is empty space.
Poor Three Good Loses Conduction Convection
Cold water pipes at home freeze in the winter and could burst as ice has a larger volume than water, give a solution and a reason.
Put insulation around them in order for the heat not to be lost ie rubber/plastic/felt
Label a vacuum flask
In workbook
Plastic cap on a vacuum flask cuts down … as it is a … Conductor. Double walled glass container cuts down … As it … Vacuum cuts down … And … As it cannot … Due to the absence of … Plastic container provides … As it …
Conduction Poor Radiation Reflects Convection Conduction Cannot occur Particles Insulation Traps heat
Thermal radiation is energy transfer by…
Electro magnetic waves
All bodies emit …
Thermal radiation (more if hotter)
…surfaces are better absorbers and emitters of thermal radiation than … Surfaces
Dark matt
Light shiny
Non metals are bad conductors as they do not..
Contain free electrons
Materials such as fibre glass are … Insulators as they contain pockets of trapped …
Good
Air
Convection takes place only in
Liquids and gases
Heating a liquid or a gas makes it … Dense
Less
Convection is due to a hot liquid or gas …
Rising
A radiator has a large surface area so it can
Lose heat easily
Large objects lose heat … Than small objects do
More easily
4 ways a building can reduce heat loss
- aluminium foil behind radiators
- cavity wall insulation
- double glazing
- loft insulation
Conduction
The transfer of heat through matter (the matter does not move) passing the energy from one vibrating atom to the next
Are metals good conductors
Yes, while non metallic substances are poor conductors of heat
Poor conductors of heat are also known as
Insulators
What is the best insulator of heat
A vacuum
Only heat can pass through a vacuum via
Radiation
Air is also one of the best insulators as
Very little heat can pass through by conduction
Uses of poor conductors
Food containers ie styrofoam
Example use of good conductors of heat
Cooking pots and pans
Convection
The transfer of heat from one place to another by the movement of the heated material itself
Convection occurs in
Only liquids and gases
Convection produces a convection current where
Hot air/liquid will rise and expand while colder air/liquid sinks like a circle
Radiation
The transfer of energy through a vacuum in the form of electromagnetic waves
Dark or black with dull surfaces … Heat and .., heat easily
Radiate/emit
Absorb
Objects with shiny and smooth surfaces are .. Radiators and absorbers of heat
Bad
Explain why a string vest may keep you cooler in the winter
As air particles are captured in the holes of the vest, which make an insulation
What can be used on doors in houses to prevent heat loss
Plastic strips along the seems for insulation
Kinetic energy
Movement energy, car, running, blood
Gravitational potential energy
Energy gained by reaching a higher point, rocket, lift, jumping
Elastic potential energy
Energy gained by stretching, rubber band, spring, trampoline
Nuclear energy
Energy stored in the nucleus of atoms, bomb, atom nucleus, power station
Sound energy
Energy that projects noise, speaking, instrument, ultrasound
Thermal energy
Heat energy, fire, sun, animals
Chemical energy
Energy stored in things like food, batteries, petrol
Electrical energy
Energy with an electrical current, chargers, radio, TV
Light energy
Energy that produces a beam, firework, lightbulb, sun
Write the energy transformation equation
Input energy –> useful energy output + wasted energy output
Popping a balloon energy transformation
Kinetic –> sound + kinetic
Wind up torch energy transformation
Elastic potential + sound –> light + thermal
How does convection force a hot air balloon to fly
Hot air is less dense than cold air so therefore it rises, forcing the balloon to fly as the hot air cannot escape
Some fossil fuels
Coal
Oil
Natural gas
Main energy source of the planet is
Fossil fuels
What is a non renewable energy source
One that effectively cannot be replaced once it has been used
Burning fossil fuels lets
CO2 off into the atmosphere which is a greenhouse gas
Greenhouse gases .. The suns heat in the earths atmosphere and cause the average temp of the atmosphere to .. This is called …
Trap
Rise
Global warming
Burning … Releases more CO2 than any other fossil fuel when burnt
Coal
When … Is burnt it releases the least amount of CO2 into the atmosphere in fossil fuels
Natural gas
There is no way of avoiding the … Of carbon dioxide when fuels are burnt
Release
Most types of coal and oil contain
Sulphur
When sulphur is burnt it converts into
Sulphur dioxide
When sulphur dioxide mixes with water in the atmosphere it forms
Acid rain
Acid rain causes damages to
People, buildings, trees, lakes
It is possible to remove sulphur and sulphur dioxide, however
It increases the cost of production
Nuclear reactors use .. To produce energy
Uranium (a particular isotope of it)
Even though nuclear reactors need a small amount of uranium it is in
Limited supply
Nuclear fuel is considered
Clean
The cost of nuclear fuel is very low however there is a … Risk of accidents and when the station is finished with it is hard to get rid of materials such as … If they are released it can cause long lasting affects to … Nuclear power stations are also … To build
High
Plutonium and uranium
Living things
Very expensive
When burning energy sources, the heat is used to … water, causing high … steam that makes the blades of a turbine … The turbine is used to spin the generator which makes …
Warm
Pressure
Spin
Electricity
Renewable energy source is one that
Will not run out ie wood
Wood when burnt produces
Fossil fuels
What is hydroelectric power
These stations use GPE of water in high reservoirs built in mountains, converted to KE when the water is releases and flows down the mountain to the power station below, as it drops the turbine is used to turn the generators
Hydroelectric power is renewable because
When it rains the reservoirs are refilled
Hydroelectric powers only disadvantage is
Spoiling landscape
Possibly destroying/altering natural habitat for wildlife
Tidal power is
A mass amount of water generates power by turning turbines as the tide flows into a dammed river estuary, as the tide falls and the water flows out of the estuary the turbines are spun again , however not many places are suited for this
Wind power is
Only windmill plants where a lot of wind blows for a significant proportion of the year, can ruin landscape, cause noise pollution, kill birds and bats at night
Solar power is
Solar cells which convert light energy directly into electrical energy however not efficient and expensive, they absorb thermal radiation and use it to heat water
Geothermal energy is
Heat energy stored deep inside the earth, found in volcanic regions, decay of radioactive elements such as uranium, iceland used to drive the turbines in electricity generation stations, water also used to provide heating by piping directly to houses, can also be used in areas without hot springs in rock layers a few metres deep hot enough to produce steam
Different types of power station differ in
Speed with which they can meet changes in demand for electricity
Early morning demand
Hugh
Winter demand
High
Nuclear power … Meet immediate energy surge demands
Cannot
As it takes a long time to heat up
Fossil fuel burners can start easier and quicker but
Will still take time before they start to produce electricity
Hydroelectric power is reliable and
Can quickly produce electricity
Wind power producing is totally dependent on
The strength, direction and frequency
The cost of producing nuclear energy
Is low but to build the stations is very expensive, the pay back time is long and demolition process is slow and expensive
Cost of windfarms
Is much lower than nuclear however it produces less energy so payback time is still long
