energy transfers

Question 1

Describe the properties of heat radiation

Answer 1

• it travels in straight lines
• it can travel through a vacuum
• it can reflect off surfaces
• it is an electromagnetic wave much like light
• it travels at the speed of light
• it is a transverse wave

Question 2

Give an example of a chemical store

Answer 2

battery

coal- fuel

food

Question 3

Give an example of a nuclear store

Answer 3

Uranium in a nuclear power station

Fusion occurring in the Sun

Question 4

Solids are good conductors

Liquids and gases do not conduct heat well but they do convect heat easily, why?

Answer 4

Liquids and gases have particles which are further apart and have weak forces between them- poor conductors

Liquid and gases have particles can move freely

Convection occurs when particles gain energy (heat up) expands and move from hot to cold regions

Question 5

Why are metals good conductors of heat

Answer 5

Conduction occurs when heat is transferred through a material from particle to particle

Metals have free electrons which help heat transfer through the metal from particle to particle

Question 6

How does heat travel from the hot stove to a potato in the water?

Answer 6

Conduction from the stove to the metal pan- they are in contact

Conduction through the metal pan

Conduction from the pan to the water- they are in contact

Convection to the potato- hot water expands (is less dense) and rises

Conduction through the potato

Question 7

What are the disadvantages of wind power?

Answer 7

• you need a large area and a large number to replace one power station
• it is not reliable- no wind, no power
• they are a danger to birds on land and boats if in the sea
• they are loud and some say unsightly

Question 8

Why are solids better conductors of heat than liquids and gases?

Answer 8

Conduction occurs when heat is transferred through a material from particle to particle

In solids, the particles are close together and the forces between particles are stronger.

Question 9

What are the disadvantages of nuclear power?

Answer 9

• non-renewable source
• creates radioactive waste which takes thousands of years to decay to a safe level
• expensive to build, maintain and decommission
• the possibility of a meltdown causing environmental damage

Question 10

What are the advantages of coal, oil or gas power stations?

Answer 10

they are reliable- produce a constant supply

• much of the existing infrastructure is set-up for fossil fuels
• at them moment fossil fuels are relatively cheap

Question 11

What are the advantages of wind power?

Answer 11

• renewable energy source
• does not use fossil fuels
• does not produce carbon dioxide or other pollutants

only a small number of turbines would be needed

Question 12

How is energy shifted/transferred from the power station usefully and wastefully?

Answer 12

Usefully- Electrically via wires

Wastefully- Heating from furnace, wires and cooling towers

Radiated as sound from generator

Radiated as light from furnace

Question 13

Give an example of a kinetic store

Answer 13

car, moving

spaceship, moving

bullet moving

generator turning

Question 14

The fleece reduce heat loss in two ways? Explain

Answer 14

The fleece traps air

air is a poor conductor- reduces heat loss by conduction

air cannot move- no convection currents set up- reduces heat loss by convection

Question 15

What are the disadvantages of a hydroelectric power station?

Answer 15

• flooding of valleys and loss of habitats
• can only be built in areas which are mountainous.
• flooding of valleys and displacement of communities
• expensive to build

Question 16

How does energy transfer or shift from the chemical store of a battery to the thermal store of a bulb?

Answer 16

Electrically- charge moves in wires

Question 17

Which container will heat up the quickest?(colours)

Answer 17

The matt black container

Matt black surfaces are good absorbers of heat radiation

Shiny silvery surfaces will reflect heat radiation

Question 18

Give an example of a thermal store

Answer 18

hot pan

hot water in a kettle

the filament in a toaster

a human body

Question 19

What are the 8 stores of energy?

Answer 19

Chemical

Thermal

Gravitational

Kinetic

Vibrational

Nuclear

Electrostatic & magnetic

Elastic

Question 20

How does energy transfer or shift from a stretched elastic in a catapult to moving stone?

Answer 20

mechanically- elastic exerts a force on the stone

Elastic store of elastic is emptied

Kinetic store of stone is filled

Question 21

How is energy wastefully shifted/transferred from the wind turbine

Answer 21

Energy is wastefully shifted/transferred from the wind turbine via radiation (sound) and heating from wires and generato

Question 22

What energy store does biomass possess?

Answer 22

Chemical store

Question 23

Give an example of electrostatic & magnetic energy store

one of each!

Answer 23

Electrostatic

Two similarly charged particles near each other

Charged van de Graaf generator

Magnetic

North and north pole of a magnet pushed together

North pole of a magnet and south pole of an electromagnet pulling in a speaker cone

Question 24

advantage of nucleus power

Answer 24

Produces no polluting gases.
Does not contribute to global warming.
Very low fuel costs.
Power station has very long lifetime.

Question 25

advantage of geothermal

Answer 25

advantages MP13.consistent/reliable power
output;
MP14. does not take up a lot of land space;

Question 26

disadvantage of geothermal

Answer 26

can only be built in

geologically active areas/owtte;

Question 27

advantages of solar panels

Answer 27

MP3.can be put on existing

buildings

Question 28

disadvantage of solar panels

Answer 28

only generates electricity when it is sunny / eq;
MP5.would require a large area of panels;
MP6.idea of visual pollution;

Question 29

advantages of any renewable resources

Answer 29

MP1.resource will not run out; MP2.no polluting gases produced;

Question 30

describe the process of the air movement convention

Answer 30

air is heated by fire 
molecules speed up and gain ke 
they spread out 
air becomes less dense 
it rises 
it is replaced by cold denser air 
the air above cools down, becomes denser and sinks 
there is a convection current

Question 31

how vacuum flask reduces heat transfers

Answer 31

plastic is a bad conductor
prevents convection to the outside
vacuum has no particles so no conduction or convection
silver surfaces are good at reflecting heat