Brainscape's Knowledge GenomeTM

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


See full index

Physics > Thermal Physics > Flashcards

Thermal Physics Flashcards

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

What is the internal energy equal to

A

The sum of all the kinetic energies and potential energies of all its particles

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

How are all the kinetic energies and potential energies distributed in a body

A

Randomly distributed

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

What are the two ways you can increase the internal energy of a system

A
  • do work on the system to transfer energy to it (e.g moving its particles/changing its shape)
  • increase the temperature of the system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens to the internal energy as the state of the substance changes

A

The internal energy also changes

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

Why does the internal energy change when when the substance exchanges state

A

The potential energy of the system changes while the kinetic energy of the system is kept constant

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

How can we demonstrate that if a substance changes state the internal energy also changes

A

By measuring the temperature id water as it boils
- the temperature increases up until 100 degrees Celsius after which the energy gained through heating the water is no longer used to increase the temperature ( and therefore the kinetic energy) but instead is used to break bonds between water molecules so it can change state to water vapour and so the potential energy is increased

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

What equation can you use to measure the amount of energy required to change the temperature of a substance

A

Q = m x c x change in temp Q=energy required m=mass c=specific heat capacity

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

What is the definition of specific heat capacity

A

Is the amount of energy required to increase the temperature of 1kg of a substance by 1 degree Celsius/1k without changing state

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

What equation can be used to measure the amount of energy required to change the state of a substance

A

Q = m x l Q=energy required m=mass l=specific latent heat

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

What is the definition of specific latent heat

A

The amount if energy required to change the state of 1kg of material, without changing its temperature

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

What are the two types of specific latent heat

A

Specific latent heat of fusion ( when solid changes to liquid )
Specific latent heat of vaporisation ( when liquid changes to gas )

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

What do the gas laws describe

A

The experimental relationship between pressure volume and temperature for a fixed mass of gas

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

Are the laws based on a theory or from observation and experimental evidence

A

From observation and experimental evidence which means they are empirical in nature

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

What are the three laws

A

1 - Boyle’s law
2 - Charles’ law
3 - The pressure Law

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

What is Boyle’s and it’s equation

A

When temperature is a constant and pressure and volume are inversely proportional
PV = K

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

What is Charles’ law and its equation

A

When pressure is a constant, volume is directly proportional to absolute temperature
V/T = K

17
Q

What is the pressure law and its equation

A

When volume is constant, pressure is directly proportional to absolute temperature
P/T = K

18
Q

What temperature measured in when using the gas laws

A

Kelvin

19
Q

What is the value of absolute zero

A

0K = -273°C

20
Q

What happens to particles when they reach absolute zero and what happens to a gas

A

They have no kinetic energy and the volume and pressure of a gas are zero

21
Q

What equation do you get when you combine all the laws of gas

A

PV/T = K

22
Q

What dies K equal to in the equation PV/T = K and what is the rearranged equation

A

K = nR where n is the number of moles and R is the molar gas constant and the new equation is PV = nRT

23
Q

What is the value of the molar gas constant

A

8.31

24
Q

What is the value of 1 mole of a substance

A

6.02 x 10^23 atoms/molecules

25
Q

What is the equation to covert between the number of moles and the number of molecules

A

N = n x Na N=the number of molecules n = the number of moles Na= the Avogadros constant

26
Q

What are the two ideal gas equations

A

PV= nRT and PV= NkT
N is the number of molecules
K is the Boltzmann constant

27
Q

What is the molar mass and how can it be found

A

Is the mass ( in grams ) of one mole of a substance and can be found by finding the relative molecular mass which is approx equal to the sum of all the nucleons in a molecule of the substance

28
Q

What is the equation used to calculate work done on a gas to change its volume when it’s at constant pressure ( this is usually done through the transfer of thermal energy)

A

Work done = p x change in V
P = pressure
V = volume

29
Q

How do you find the work done on a pressure volume graph

A

The area under the graph

30
Q

what is Brownian motion

A

is the random motion of larger particles in a fluid caused by collisions with surrounding particles

31
Q

how can Brownian motion be observed

A

looking through at smoke particles under a microscope

32
Q

what did Brownian motion contribute evidence to

A

the existence of atoms and molecules

33
Q

how can you use the simple molecular model to explain Boyle’s law

A

if you increase the volume of a fixed mass of gas, its molecules will move further apart so collisions will be less frequent therefore pressure decreases

34
Q

how can you use the simple molecular model to explain Charles’ law

A

when the temp of a gas is increased, its molecules gain kinetic energy meaning they will move more quickly and because pressure is kept constant the molecules move further apart and volume is increased

35
Q

how can you use the simple molecular model to explain pressure law

A

when the temp of a gas is increased, its molecules gain kinetic energy meaning they will move more quickly, as a volume is constant the frequency of collisions between molecules and their container increases and they collide at higher speeds therefore pressure is increased

36
Q

what does empirical in nature mean

A

they are not based on a theory but arose from observation and experimental evidence

37
Q

what are the 5 assumptions made in the molecular kinetic theory

A
  • no intermolecular forces act on the molecules
  • the duration of collisions is negligible in comparison to time between collisions
  • the motion of molecules is random, and they experience perfectly elastic collisions
  • the motion of the molecules follow newtons laws
  • the molecules move in straight lines between collisions

Physics (18 decks)

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