Topic 3 - Thermal Physics

Question 1

temperature

Answer 1

scaler
K or ˚C
273K = 0˚C

Question 2

Heat

Answer 2

friction creates heat ENERGY
Q = thermal energy flow due to temperature change
Joules or calories

Question 3

Internal Energy

Answer 3

total internal energy of all molecules
Ke, PE or intermolecular forces

Question 4

specific heat capacity

Answer 4

different for each substance
c = Q/(m∆T)

Question 5

thermal capacity

Answer 5

Q = c∆t=T

Question 6

molecular theory

Answer 6

solid
* minimum vibrations
* “weak”
* strong bonds
* no lateral or rotational movement

liquid
* weaker bonds
* more vibration
* there is movement
* particle bonds break and reform

gas
* really strong virations
* no bonds
* lots of movement

Question 7

Types of : heat transfer

Answer 7

conduction
* when things touch heat is transferred from particle to particle

convection
* a fluid and heat transfer (wind ie heat rises)

radiation
* IR rays

Question 8

what is : pressure

Answer 8

Force/Ares
N/m^2
Pascal (Pa) or Atmospheres (atm)

Question 9

Ideal Gases

Answer 9

• Perfectly elastic (∆KE = 0)
• Perfect sphere
• No IMF’s (PE = 0)
• Particles are infentesimely small, volume doesn’t matter (unless changed)

Question 10

What is : Piston

Answer 10

• since piston does force on gas and displacement, it does work onto a gas
  F∆x = W = ∆KE = p∆V

Question 11

Types of PV=nRT changes

Answer 11

• isovolumetric / isochoric - constant v
• isothermal - same temperature
• isobaric - constant pressure