1. A2 Unit G484: The Newtonian World
Module 1: Newton’s laws and momentum
• Newton’s laws of motion
• Collisions
Module 2: Circular motion and oscillations
• Circular motion
• Gravitational Fields
• Simple harmonic oscillations
Module 3: Thermal Physics
• Solid, liquid and gas
• Temperature
• Thermal properties of materials

2. Module 3: Thermal Physics
• Solid, liquid and gas • Temperature • Thermal properties of materials

3. What is the difference between heat and temperature?
Is there a
maximum temperature?

4. 4.3.2 Temperature You should be able to:
Explain that thermal energy is transferred from a region of higher temperature to a region of lower temperature;
(b) Explain that regions of equal temperature are in thermal equilibrium;
(c) Describe how there is an absolute scale of temperature that does not depend on the property of any particular substance (ie the thermodynamic scale and the concept of absolute zero);
(d) Convert temperatures measured in kelvin to degrees Celsius (or vice versa):
T (K)= θ (°C) ;
(e) State that absolute zero is the temperature at which a substance has minimum internal energy.

5. What unit is this? °C

6. °C What unit is this? The Celsius scale is an absolute scale.
It is the absolute thermodynamic scale minus exactly.
Absolute scale/K
Celsius Scale/oC
Absolute zero
Triple point of water
273.16
0.01
Ice point
273.15
0.00
Steam point
373.15
100.00

7. Why did Einstein win a Nobel prize?
Because of his work on the photoelectric effect and on kinetic theory.

8. The First Law of Thermodynamics
Change in Internal Energy = Heat Transfer + Work Done ΔU = ΔQ + ΔW
i.e. if you put energy into a system, its internal energy will increase

9. An Obvious Law of Thermodynamics
Thermal energy is transferred from a region of higher temperature to a region of lower temperature.

10. The Zeroth Law of ThermodynamicsB C
If A is in equilibrium with B, and B is in equilibrium with C, then A and C must be in equilibrium.

11. Read pages in APFY
Complete questions 1,2,3 and 4 on page 305
The rms speed of the molecules in a gas is 600ms-1 and the mass of the molecules is 4.6 x kg. What is the temperature of the gas in degrees Celsius?
127oC

12. 4.3.3 Thermal properties of materials
You should be able to:
Define and apply the concept of specific heat capacity.
(b) Select and apply the equation E = mcΔθ
(c) Describe an electrical experiment to determine the specific heat capacity of a solid or a liquid.
Describe what is meant by the terms latent heat of fusion and latent heat of vaporisation.

13. Specific Heat Capacity
The specific heat capacity is the energy needed to raise the temperature of 1 kg by 1 K
ΔU = m c Δθ
change in = mass x specific heat x temperature
internal energy capacity change

14. Calculating the specific heat capacity of a metal

15. Calculating the specific heat capacity of a metal
mm= mass of metal [kg] =
cm = s.h.c of the metal [J kg-1 K-1] = ?
θm = initial temperature of the metal [K or oC] =

16. Calculating the specific heat capacity of a metal
mw= mass of water [kg] =
cw = s.h.c of the water [J kg-1 K-1] = 4180 J kg-1 K-1
θw = initial temperature of the water [K or oC] =

17. Calculating the specific heat capacity of a metal
Once in thermal equilibrium…
θf = final temperature of the water and metal =

18. Calculating the specific heat capacity of a metal
Thermal energy lost by metal = mmcmΔθ
Thermal energy gained by water = mwcwΔθ
θw final = θm final
mmcmΔθ = mwcwΔθ
cm = mwcw(θw final – θw initial)
mm(θm initial – θm final)