Brainscape's Knowledge GenomeTM

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


See full index

IGCSE Physics > Thermal physics > Flashcards

Thermal physics Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Pressure

A

Force(N)/Area(m^2)

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

Pressure in liquid

A

Density x gravity x height

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

Atmospheric pressure

A

Density x gravity x height

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

Manometer

A

Measures pressure exerted by a fluid

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

Brownian motion

A

the random motion of microscopic particles when observed through a microscope

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

What does the movement of smoke particles tells you about air molecules [3]

A

1) Air molecules exist
2) Air molecules collide with the smoke particles
3) Air molecules are moving randomly

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

Change of state [2]

A

1) The only thing that changes is its energy
2) Changes of state are physical changes and so they are reversible

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

effect on the pressure of the gas as it heated at a constant volume [3]

A

1) Pressure increases
2) More frequent collision between the gas molecules and walls of container
3) Because gas particles have more kinetic energy from increased temperature

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

Define Absolute zero

A

1) The lowest possible temperature / –273 °C / 0 K
2) Particles have the least kinetic energy

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

Convert from kelvin to celcius

A

[celcius]+273= Kelvin

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

Why do small particles move randomly?

A

1) Air molecules move randomly
2) Air molecules pushes the small particles around
3) These small particles undergo brownian motion

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

Evaporation explained using kinetic particle model [2]

A

1) Higher kinetic energy cause faster moving molecules
2) Molecules escape from the water surface

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

The movement of the gas molecules

A

1) High speed
2) Randomly in all directions

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

Kinetic energy equation

A

Ek = 1/2mv^2

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

gravitational potential

A

ΔEP = mgΔh

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

Energy conservation [2]

A

1) Energy cannot be created or destroyed, only transferred from store to store
2) There is a finite amoutn of energy in a closed system that can be transferred from one store to another

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

Why is energy transfer not 100% efficent

A

Energy can be dissipated (spread out) to the surroundings by heating and radiation

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

Why is work done = to energy transfer?

A

1 joule = 1 Nm

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

100Nm convert into Joules

A

100Joules

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

What are the 2 types of work?

A

1) A force acting over a distance (Mechanical transfer pathway)
2) A flow of charged particles (electricaly transfer pathway)

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

Work done on objects in equilibrium

A

1) When object is in equilibrium all forces acting on the object is balanced
2) Work is done on the object to change its motion

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

Work done

A

Force x Distance (moved in the direction force applied)

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

Unit of work

A

Joules or Nm

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

Define Power

A

1) Amount of energy transferred per unit time (energy per second)
2) Amount of work done per unit time

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

Useful energy vs Wasted energy

A

1) Useful energy is energy transferred for its intended purpose
2) Wasteful energy is energy transferred not useful for this purpose

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

Define efficency

A

The ratio of useful energy output to total energy input

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

4 types of energy transfer pathways

A

1) Mechanical: When a force acts on a body eg. collision
2) Electrical: Electricity transfer energy from a power source, such as a cell delievering it to components in a circuit
3) Heating: Energy can be transferred from radiation conduction, convection
4) Radiation: Light and sound carry energy and can transfer this from 2 points

28
Q

Efficency %

A

(Useful energy output/Total energy input) x100

29
Q

F formula for energy or work

A

Change in energy(J) / time (s)
Work (Nm) / t (s)

30
Q

Power formula in a circuit

A

Voltage x current

31
Q

Ways energy is stored

A

1) kinetic,
2) gravitational potential,
3) chemical,
4) elastic (strain),
5) nuclear,
6) electrostatic
7) internal (thermal)

32
Q

Where do most energy sources on earth come from

A

The sun

33
Q

What 3 energy do not come from the sun

A

1) Geothermal- heat from earth’s core
2) Nuclear- elements that make up a small portion of earth’s crust
3) Tidal- gravitational attraction of the moon

34
Q

3 fossil fuel

A

Coal
Natural gas (mostly methane) which is used in domestic boilers and cookers
Crude oil which is refined into petrol, diesel, and other fuels

35
Q

Define renewable source

A

A resource that can be replenished as it is used / is replaced (by nature) in less than a (human) lifetime

36
Q

Hydroelectrical dam

A

A hydroelectric dam transfers energy from the gravitational potential energy store of the water to its kinetic energy store mechanically to generate electricity

37
Q

Describe nuclear fusion

A

Small nuclei fuse together to form bigger nuclei

38
Q

Why is nuclear fusion not used as an energy source

A

Fusion requires very high temperatures
That cannot be produced currently

39
Q

To describe how the wind turbine produces electricity

A

1) Moving air spins the blades
2) kinetic energy from that turns on a generator
3) Generator produces electrical energy

40
Q

Explain how the tidal barrage (dam) produces electricity

A

1) Water has energy in its kinetic store
2) When the tide comes in and out the water goes through the turbine
3) turbine rotates and generates electricity

41
Q

To describe how energy released from fission reactions is used to generate electricity

A

1) Energy released from the nuclei fusion is transfered into the thermal store of water to produce steam
2) Steam turns a turbine
3) Turbin turns a generator which generates electricity

42
Q

Why Pressure is constant at constant depth

A

Because given it is the same liquid (same density) and on the same planet, the depth is the only factor affecting the pressure, so at the same depth the pressure remains the same

43
Q

Why do you need a large amount of force to break a small chunk of rock?

A

1) The attractive forces between atoms in the rock are strong
2) Work must be done to separate the atoms

44
Q

Why is that when water reaches its boiling point the temperature stops increasing?

A

All energy is used up by the particle to overcome intermolecular forces of attraction between water molecules, turning them from liquid to gas.

45
Q

Describe and explain 2 applications of thermal expansion

A

1) Expansion gaps in railway tracks, in hot weather the tracks expand and can buckle, the gap allows expansion with no damage to the track
2) Expansion gaps in roads, in hot weather the surface expand and can buckle, the gap allows expansion with no damage to the surface

46
Q

How volatile liquids cool the skin [4]

A

1) More energetic molecules escape from the liquid
2) molecules with less kinetic energy are left behind
3) Temperature of liquid decreases
4) Thermal energy is lost by skin

47
Q

Explain why are Liquids are incompressible

A

1) The molecules are touching
2) There are large intermolecular forces to stop them from moving closer

48
Q

Define Specific heat capacity

A

energy / heat required to raise the temperature by 1°C of 1 kg of a substance

49
Q

Specific heat capacity formula

A

Change in energy = mass x specific heat capacity x change in temperature

You can find the amount of thermal energy transferred into x substance

50
Q

Conduction vs convection

A

1) Conduction is where heat transfer between objects
2) Convection is heat transfer within the fluid

51
Q

Describe convection in water

A

1) As the water is heated, energy is transferred to the kinetic energy store of the water molecules, causing them to move faster
2) This increases the volume of the water, and hence decreases its density 3) The warm water rises.
4) Away from the heat the water cools, decreases in volume and falls, creating a convection current

52
Q

How does these 2 features keep liquid in a vacuum flask warm:

Shiny silver surface

The vacuum between the silvered surface (No particles)

A

1) Reflects thermal radiation
2) Heat loss by conduction and convection cannot take place because particles are needed for conduction or convection to take place

53
Q

To describe thermal conduction in terms of particles through a metal [3]

A

1) The delocalised electrons gain energy
2)Energy is transferred through the metal as electrons move
3) Energy transfer from high to low temperature regions

54
Q

Describe in terms of molecules why the temperature of a spoon increase when placed in hot liquid

A

1) The molecules of the hot liquid collide with the surface of the spoon
2) Energy is transferred from the hot liquid to the spoon
3) The amplitude of the vibration of the spoon’s molecules increase, this increases the spoon’s temperature.

55
Q

State what happens to the volume of molecules When gas changes to solid

A

Nothing changes

56
Q

Explain why balloons shrink in size when its cooler in terms of particle theory

A

1) particles have lower kinetic
energy
2) on average collide less often
3) Thus less pressure on rubber
4) Which pulls balloon material into smaller size

57
Q

What are the 3 sources of energy that isnt from the sun

A

1) Geothermal
2) nuclear
3) Tidal

58
Q

How is energy released in the sun

A

Nuclear fusion

59
Q

The research to investigate how energy released by nuclear fusion can be used to produce electrical energy on a large scale is being carried out

A

JUST FOR U TO KNOW

60
Q

pV=constant explained

A

Pressure Volume = constant
for a fixed mass of gas at constant temperature

61
Q

What does the rise in the temperature of an object also rises?

A

Its internal energy

62
Q

Boiling vs Evporating

A

1) Evaporation is slower, boiling is faster
2) Evaporation leads to cooling. boiling does not
3) Evaporation happens on the surface, boiling occurs throughout

63
Q

If the temperature T of an ideal gas is constant, then Boyle’s Law is giv

A

P is proportional to 1/V

64
Q

The relationship between the pressure and volume for a fixed mass of gas at constant temperature can also be written as

A

P1 V1=P2 V2 2

65
Q

Explain why pans have shiny surfaces [2]

A

1) poor emitters of radiation
2) Reduces energy loss

66
Q

Explain in terms of particles, why is it difficult to compress liquid? [2]

A

1) Liquid particles are touching
2) forces between particles are quite huge

IGCSE Physics (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions