Thermal Physics Flashcards Preview

Physics - AQA A Level > Thermal Physics > Flashcards

Flashcards in Thermal Physics Deck (28):
1

Internal energy

Energy of its molecules due to their individual movements and positions

2

Internal energy increases

If work is done on the object
If energy is transferred to it

3

If internal energy energy stays constant

No energy transfer
Energy transfer by work done and heat transfer cancels out

4

First law of thermodynamics

ΔInternal energy = energy transfer due to work done or heating

5

Internal energy is the sum of...

Random distribution of the kinetic and potentials energies of its molecules

6

Thermal equilibrium

No thermal heat transfer

7

Absolute zero

Where a substance has minimum internal energy

8

Specific heat capacity

Energy required to raise the temperature of a hunky of mass by 1K

9

Inversion tube experiment

GPE → thermal energy
nmgh → mcΔT

10

Measuring specific heat capacity using electrical methods

Electrical energy → thermal
IVt → mcΔT

11

Latent heat

Where heating results in no temperature change during a change in state

12

Latent heat of fusion

Energy required to melt a solid

13

Latent heat of vapourisation

Energy required to vaporise a liquid

14

Latent heat of sublimation

Energy required to heat a solid to its gas

15

Latent heat equation

Q = ml

Q - energy required
m - mass
l - specific latent heat

16

Boyle’s Law

pV = k

Fixed mass and temperature

17

Charles’ law

V/T = T

Fixed mass and pressure
(Used to find absolute zero)

18

The pressure law

p/T = k

Fixed mass and volume

19

Brownian motion

Random and rapid motion of gas particles

20

Avogrado constant

Number of atoms in 12g of carbon-12

21

Ideal gas equation

pV = nRT

R- molar gas constant

22

Boltzmann constant

pV = NkT

k = R/ Avogadro’s

23

Root mean square speed of gas molecules

[ c₁² + c₂² + c₃² +...] ½
C rms = [ ————————]
[ N ]

24

Kinetic theory equation

pV = ¹⁄₃Nm(Crms)²

25

Ideal gases

1. Point molecules
2. No attractions
3. Continual random motion
4. Elastic conditions
5. Short impact times

26

Mean Ek of a gas molecule

= ³⁄₂kT

27

Ek of n moles of an ideal gas

= ³⁄₂nRT

28

Internal energy of an ideal gas

= ³⁄₂nRT