4 Energy Transfers and Resources Flashcards
What are the 8 stores of energy?
Chemical
Thermal
Gravitational
Kinetic
Nuclear
Electrostatic
Magnetic
Elastic
List the 4 ways in which energy can be transferred
mechnically- by a force
electrically- movement of charge
radiation- light or sound
heating- hot to cold
What is the Principle of Conservation of energy?
Energy cannot be created or destroyed only transferred from one store to another
What is the equation for efficiency?
Efficiency = useful energy output / total energy input
Give an example of a chemical store
battery
fuels (eg petrol)
food
Give an example of a nuclear store
Uranium in a nuclear power station
Fusion occurring in the Sun
Give an example of a kinetic store
car, moving
spaceship, moving
bullet moving
generator turning
Give an example of a thermal store
hot pan
hot water in a kettle
the filament in a toaster
a human body
Give an example of gravitational store
Water behind a dam
Person at the top of a slide
Spaceship in orbit around Earth
Give an example of electrostatic & magnetic energy store
(one of each!)
Electrostatic
Two charged particles near each other
Charged van de Graaf generator
Magnetic
Two magnets pushed together
Give an example of an elastic store
stretched elastic in a catapult
bent ruler
stretched spring in a clockwork toy
What are the 3 methods of heat transfer?
Conduction
Convection
Radiation
What is conduction?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/425/q_image_thumb.jpg?1514552599)
Conduction occurs when heat is transferred through a material from particle to particle
Why are solids better conductors of heat than liquids and gases?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/346/q_image_thumb.jpg?1514552773)
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.
Why are metals good conductors of heat?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/336/q_image_thumb.jpg?1514552772)
Metals have free electrons which help heat transfer through the metal from particle to particle
What is convection?
Convection occurs in a liquid or a gas
when particles heat up and gain energy,
take up more volume,
this hot region becomes less dense and rises,
cold denser region falls,
creating a convection current
Using convection describe how heat is transferred in a room.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/417/q_image_thumb.jpg?1514552257)
- air above the radiator is heated
- hot air expands and becomes less dense
- hot air rises and moves along the ceiling
- hot air cools (becomes denser) and falls
- cool air is pulled towards radiator to replace hot air which moved upward
What is radiation of heat?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/330/q_image_thumb.jpg?1514551736)
an electromagnetic wave
so
- it travels in straight lines
- it can travel through a vacuum
- it travels at the speed of light
- it is a transverse wave
State the different ways in which heat is transferred from a thermos flask.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/427/a_image_thumb.jpg?1514553987)
How does heat travel from the hot stove to a potato in the water?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/339/q_image_thumb.jpg?1514551947)
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
Name the initial energy store and final energy store when a roller coaster accelerates down the first slope.
Which of the 4 types of energy transfer is taking place?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/335/q_image_thumb.jpg?1514315846)
Initial store: Gravitational store of the roller coaster
Final store: Kinetic store of the roller coaster along with the thermal store of the track, wheels and surroundings.
Energy is transferred mechanically.
What are the disadvantages of wind power?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/342/q_image_thumb.jpg?1514538502)
- large number to replace one power station
- it is not reliable- no wind, no power
- danger to birds on land and boats in the sea
- they are loud and some say unsightly
-
What are the disadvantages of nuclear power?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/347/q_image_thumb.jpg?1514451209)
- 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
Which thermometer will record the highest temperature?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/349/q_image_thumb.png?1514551430)
The thermometer nearest the matt black surface.
The hot metal radiates heat to the surroundings and the matt black surface will radiate heat at a quicker rate.
What are the advantages of coal, oil or gas power stations?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/350/q_image_thumb.jpg?1514538673)
- they are reliable- produce a constant supply
- at them moment fossil fuels are relatively cheap
This hot cup of tea holds a thermal store of energy.
How is the energy transferring from this cup of tea to the surroundings?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/352/q_image_thumb.jpg?1514281334)
by heating
Use the conservation of energy to work out how much energy is used for respiration in a cow.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/353/q_image_thumb.jpg?1514550474)
Conservation of energy is energy cannot be created nor destroyed, it is only transferred from one store to another.
100kJ = Energy In
4kJ + 63kJ + ? = Energy Out
33kJ of energy goes to respiration in the cow
What are the advantages of wind power?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/354/q_image_thumb.jpg?1514538406)
- renewable energy source
- does not use fossil fuels
- does not produce carbon dioxide or other pollutants
How is energy transferred from the power station to our homes?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/355/q_image_thumb.jpg?1514365573)
Electrically via wires
The fleece reduces heat loss in two ways? Explain
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/357/q_image_thumb.jpg?1514554408)
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