Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Core Physics > P1.1 - The Transfer of Energy > Flashcards

P1.1 - The Transfer of Energy Flashcards

1
Q

What are the three means of heat transfer and where do they occur?

A

Radiation - via infrared in solids, liquids, gases

Conduction - in solids

Convection - in liquids and gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which two means of heat transfer involve particles (a medium)?

A

Conduction and convection involve particles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The bigger the temperature difference between a body and its surroundings, the faster the what…?

A

The bigger the temperature difference between a body and its surroundings, the faster energy is transferred by heating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How often do objects emit and absorb infrared radiation?

A

All objects continually emit and absorb infrared radiation, which is emitted from the surface of an object.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does temperature have an effect on infrared radiation?

A

The hotter an object is, the more radiation it radiates in a given time.

The colder an object is, the less radiation it radiates in a given time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe how dark, matt surfaces affect infrared radiation.

A

Dark, matt surfaces are good absorbers and good emitters of infrared radiation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe how light, shiny surfaces affect infrared radiation.

A

Light, shiny surfaces are poor absorbers and poor emitters of infrared radiation but are good reflectors of infrared radiation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain how solar hot water panels work.

A

Solar hot water panels contain water pipes under a black surface, which absorbs the radiation from the Sun to heat water in the pipes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can heated water from solar panels do?

A

Heated water from solar panels can be used for washing or can be pumped into radiators to heat a building.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

In terms of particles, what determines an object’s properties?

A

The particles are arranged differently in solids, liquids, and gases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the properties of a solid.

A

Particles in a solid are held together by strong forces of attraction.

Particles in a solid cannot move, so solids have a fixed shape.

Particles in a solid cannot move closer together, so solids cannot be compressed.

Particles in a solid do not have much energy, so they can only vibrate about their fixed positions. They have small amounts of kinetic energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why can’t a solid be compressed?

A

The particles in a solid are tightly packed together.

The particles in a solid cannot move closer together, so solids cannot be compressed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why can solids only vibrate about their fixed positions?

A

The particles in a solid do not have much energy, so they can only vibrate about their fixed positions. They have small amounts of kinetic energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the properties of a liquid.

A

They take the shape of their container as they can flow.

The forces of attraction between particles in a liquid are not as strong as those in a solid - they have a lot of kinetic energy.

Particles are already close together, so it is hard to compress a liquid.

Particles in a liquid move from place to place, so liquids flow and take the shape of their container.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain the forces of attraction between particles in a liquid.

A

The forces of attraction between particles in a liquid are not as strong as those in a solid - they have a lot of kinetic energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is it so hard to compress a liquid?

A

The particles are already close together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why do liquids take the shape of their container?

A

Particles in a liquid move from place to place, so liquids flow and take the shape of their container.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the properties of a gas?

A

There are virtually no forces of attraction between the particles - the particles are far apart.

You can compress gases because there is so much space between the particles.

Particles in a gas have more energy than those in solids and liquids - they can travel in random directions at high speeds.

They can take the shape of their container.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain the forces of attraction between particles in a gas.

A

There are virtually no forces of attraction between the particles in a gas - the particles are very far apart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why can you compress gases?

A

You can compress gases because there is so much space between the particles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do particles in a gas move?

A

Particles in a gas have more energy than those in solids and liquids - they can travel in random directions at high speeds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why do gases take the shape of their container?

A

They can take the shape of their container as their particles can move freely and randomly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is conduction?

A

Conduction is where vibrating particles pass on their extra kinetic energy to neighbouring particles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Explain how conduction works.

A

When heat is applied, the heat is given to the particles.

They vibrate more vigorously, and the vibrations spread from one particle to another until the end of the solid is reached.

The object becomes hot.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why is conduction faster in metals?

A

Metals are solids that have free electrons which can move and carry heat energy.

The electrons will move faster and collide with other free electrons, transferring heat energy quickly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What do insulators do in terms of conduction?

A

Insulators reduce heat movement by conduction?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How do insulators affect heat transfer?

A

Insulators are made up of particles, however the spaces between the particles means that the heat energy cannot be transferred as easily as it would be in a solid.

Conduction is faster in denser solids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is convection and why can’t it happen in solids?

A

Convection takes place in liquids and gases, but not in solids.

The particles in a solid cannot move.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

When does convection occur?

A

It occurs when the more energetic particles move from the hotter region to the cooler region and take their heat energy with them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe the process of convection.

A

When the particles are heated, they gain heat energy.

They move further apart, making the liquid less dense.

The warm water rises and the denser, cooler water sinks to take its place.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What currents do we get from convection?

A

This results in convection currents going up and down.

32
Q

What containers does convection work best in?

A

Convection is most efficient in roundish or squarish containers because the currents can flow more easily.

33
Q

What is evaporation?

A

Evaporation is where particles escape from a liquid. The liquid can turn into a gas.

34
Q

Does the liquid’s boiling point affect evaporation?

A

Particles can evaporate from a liquid at temperatures lower than the liquid’s boiling point.

35
Q

When will evaporation occur?

A

It will occur if:

The particles are travelling upwards and not downwards.

The particles are travelling fast enough (they have enough kinetic energy) to overcome the attractive forces of the other liquid particles.

36
Q

How does evaporation affect an object’s temperature?

A

This reduces the liquid’s overall energy - it cools down.

37
Q

How does temperature affect evaporation?

A

A higher temperature = more average energy for the particles. Evaporation is faster.

38
Q

How does density affect evaporation?

A

A lower density means weaker forces between the particles and so the particles can easily overcome these to escape.

39
Q

How does surface area affect evaporation?

A

A large surface area means more particles will be near enough to the surface to escape the liquid.

40
Q

How does airflow affect evaporation?

A

More airflow = lower concentration of evaporating substance so the air above the liquid is replaced quickly.

41
Q

What is condensation?

A

Condensation is where a gas turns into a liquid.

42
Q

How does condensation work?

A

When a gas cools, the particles in a gas slow down and lose kinetic energy. They move closer together and the gas condenses into a liquid.

43
Q

How does temperature affect condensation?

A

Lower temperature = lower particle energy so they will slow down and condense.

44
Q

How does the temperature of the surface the gas touches affect condensation?

A

Lower temperature = the rate of condensation increases

45
Q

How does density affect condensation?

A

A higher density means that the forces between the particles will be stronger, so the particles will form a liquid instead of trying to overcome the forces.

46
Q

How does airflow affect condensation?

A

Less airflow means that the substance in the air will have a higher concentration and the rate of condensation is greater.

47
Q

Where is heat radiation emitted from?

A

Heat radiation is emitted from the surface of an object.

48
Q

How does an object’s surface area affect the rate of heat transfer?

A

Objects with a large surface area lose heat faster.

Smaller objects have a larger surface area for their volume than larger objects. Therefore, smaller objects CAN cool down faster than larger objects.

49
Q

How does an object’s material and connecting material affect heat transfer?

A

If the object is on a conducting surface, more heat is lost.

If the object is a conductor, there is more heat loss.

50
Q

How do animals in Africa lose heat?

A

Animals in Africa, a hot continent, may have large ears. This gives them a large surface area and thus they lose heat more rapidly.

51
Q

How might a cooling system be adapted for heat transfer?

A

Cooling systems may have a large surface area to promote heat transfer. They may be black, too.

52
Q

What is the purpose of a vacuum flask?

A

Vacuum flasks are designed to reduce heat transfer.

53
Q

What means of energy transfer does the plastic top of a vacuum flask reduce?

A

It reduces energy transfer by:

Conduction

Convection

Evaporation

54
Q

How does the plastic top of a vacuum flask reduce conduction?

A

Plastic is a good insulator, so it reduces conduction.

55
Q

How does the plastic top of a vacuum flask reduce convection?

A

The convection currents cannot form since they are blocked by the top.

56
Q

How does the plastic top of a vacuum flask reduce evaporation?

A

Water molecules that evaporate are trapped inside the flask.

57
Q

What means of energy transfer do the silvered glass walls of a vacuum flask reduce?

A

They reduce energy transfer by:

Conduction

Radiation

58
Q

How do the silvered glass walls of a vacuum flask reduce conduction and radiation?

A

Conduction - glass is a poor conductor.

Radiation - silver reflects infrared radiation and keeps the liquid cool/warm.

59
Q

What means of energy transfer does the vacuum of a vacuum flask reduce?

A

It reduces energy transfer by:

Conduction

Convection

60
Q

How does the vacuum of a vacuum flask reduce energy transfer?

A

Conduction and convection require a medium.

A vacuum has very few particles and thus reduces conduction and convection.

61
Q

What means of energy transfer do the plastic supports of a vacuum flask reduce?

A

Conduction

62
Q

How do the plastic supports reduce conduction?

A

Plastic is a good insulator so it reduces conduction.

63
Q

What are u-values?

A

U-values measure how effective a material is as an insulator.

The lower the u-value, the better the material is as an insulator.

64
Q

What is Specific Heat Capacity?

A

Specific Heat Capacity is the amount of energy needed to change the temperature of 1kg of a substance by 1 degree.

65
Q

What is the equation for Specific Heat Capacity?

A

E = M * C * Temperature Change

E = Energy transferred in Joules

M = Mass in kilograms

C = Specific Heat Capacity in J/kg/degrees

66
Q

What are the most effective domestic methods of insulation like?

A

The most effective domestic methods of insulation give you the best annual savings.

They save you the most money yearly on your heating bills.

67
Q

What is payback time?

A

The payback time is the time it takes for the money you save on heating bills to equal the initial cost of the insulation.

68
Q

What is the formula for payback time?

A

Payback time = initial cost/annual saving

69
Q

Why are the most cost effective methods for insulation the cheapest?

A

The most cost effective methods are the cheapest because they have a short payback time. You can recover the amount of money paid in quickly.

70
Q

What is cavity wall insulation?

A

Foam placed into the gap between bricks. It reduces convection and radiation across the gap. Pockets of air inside reduce heat transfer by conduction.

71
Q

What is loft insulation?

A

A thick layer of fibreglass wool laid out across the loft floor reduces heat loss by conduction and convection.

72
Q

What is draught proofing?

A

Strips of foam and plastic around doors and windows to stop draughts blowing in - they reduce convection.

73
Q

What is a hot water tank jacket?

A

Lagging (fibreglass wool) reduces conduction and radiation.

74
Q

What are “thick curtains” good at reducing?

A

They reduce convection and radiation.

75
Q

What is double glazing?

A

It traps insulated air between the glass panes and reduces conduction and convection.

Core Physics (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions