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