Lesson 08
Review
Review the topic after the test and strengthen weak areas.
Objectives
Lesson outcomes
- Correct errors from the A2 thermal physics test using clear physics reasoning.
- Identify whether mistakes came from definitions, model choice, unit conversion, algebra, or sign convention.
- Set targeted follow-up practice for the weakest part of temperature, gases, or thermodynamics.
Syllabus
CIE 9702 syllabus points
21 linked
- 14.1.1 understand that (thermal) energy is transferred from a region of higher temperature to a region of lower temperature
- 14.1.2 understand that regions of equal temperature are in thermal equilibrium
- 14.2.1 understand that a physical property that varies with temperature may be used for the measurement of temperature and state examples of such properties, including the density of a liquid, volume of a gas at constant pressure, resistance of a metal, e.m.f. of a thermocouple
- 14.2.2 understand that the scale of thermodynamic temperature does not depend on the property of any particular substance
- 14.2.3 convert temperatures between kelvin and degrees Celsius and recall that T / K = θ / °C + 273.15
- 14.2.4 understand that the lowest possible temperature is zero kelvin on the thermodynamic temperature scale and that this is known as absolute zero
- 14.3.1 define and use specific heat capacity
- 14.3.2 define and use specific latent heat and distinguish between specific latent heat of fusion and specific latent heat of vaporisation
- 15.1.1 understand that amount of substance is an SI base quantity with the base unit mol
- 15.1.2 use molar quantities where one mole of any substance is the amount containing a number of particles of that substance equal to the Avogadro constant NA
- 15.2.1 understand that a gas obeying pV ∝ T, where T is the thermodynamic temperature, is known as an ideal gas
- 15.2.2 recall and use the equation of state for an ideal gas expressed as pV = nRT, where n = amount of substance (number of moles) and as pV = NkT, where N = number of molecules
- 15.2.3 recall that the Boltzmann constant k is given by k = R / NA
- 15.3.1 state the basic assumptions of the kinetic theory of gases
- 15.3.2 explain how molecular movement causes the pressure exerted by a gas and derive and use the 1 1
- 15.3.3 understand that the root-mean-square speed cr.m.s. is given by <c 2 > 1
- 15.3.4 compare pV = 3 Nm<c2> with pV = NkT to deduce that the average translational kinetic energy of a 3
- 16.1.1 understand that internal energy is determined by the state of the system and that it can be expressed as the sum of a random distribution of kinetic and potential energies associated with the molecules of a system
- 16.1.2 relate a rise in temperature of an object to an increase in its internal energy
- 16.2.1 recall and use W = p∆V for the work done when the volume of a gas changes at constant pressure and understand the difference between the work done by the gas and the work done on the gas
- 16.2.2 recall and use the first law of thermodynamics ∆U = q + W expressed in terms of the increase in internal energy, the heating of the system (energy transferred to the system by heating) and the work done on the system
Definitions
Required definitions
Specific heat capacity
the energy required per unit mass per unit temperature rise.
Specific latent heat
the energy required per unit mass to change state without a change in temperature.
Specific latent heat of fusion
the energy required per unit mass to change between solid and liquid without a change in temperature.
Specific latent heat of vaporisation
the energy required per unit mass to change between liquid and gas without a change in temperature.
Lesson Notes
Student guidance and lesson notes
Overview
This lesson uses the A2 thermal physics test to improve your next round of revision. The aim is to understand why errors happened, correct them properly, and decide what needs more practice.
What You Need to Know
- A useful correction explains the physics, not just the final answer.
- Most errors in this topic come from model choice, unit conversion, symbol confusion, or sign convention.
- Similar-looking questions can require different equations depending on the process taking place.
- Feedback should lead to a specific practice target.
How to Work Through It
- Sort your test errors by topic and skill: definitions, equations, models, units, or signs.
- Rewrite selected answers with the missing physics included.
- Rework at least one similar question without looking at the original solution.
- Finish with a short target for future A2 thermal physics revision.
Check Your Understanding
- Which mistake cost the most marks, and why?
- Was the weak step physics understanding, algebra, units, or exam wording?
- Can you now explain the corrected answer without reading from the mark scheme?
Common Mistakes
- Copying the mark scheme without identifying the original misconception.
- Correcting calculations while leaving the wrong model choice unchanged.
- Treating one weak question as isolated when it shows a broader skill gap.
- Ignoring sign-convention errors because the final number looked plausible.
Next Steps
- Add the weakest A2 thermal physics subtopic to your next independent revision cycle.
- Keep corrected examples available for later synoptic revision.