LuduminaPM-07 · PM-U3 · Planned
Work done on a gas
Learning objectives
Explain why rapid compression can heat gas; distinguish this from the constant-temperature pV model.
8463 §§4.3.3.3 / No Trilogy counterpart
DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.6,3.7.
Explanation
Compressing gas does mechanical work on it. If transfer to surroundings is too slow to remove that added energy, internal energy and temperature increase. This is different from a slow constant-temperature compression model.
Concepts, equations and units: Mechanical work increases internal energy; J,Pa,°C; no pΔV calculation required.
Prediction, demonstration and game exercise
Predict, observe, explain
Compare slow isothermal and fast model pump strokes; trace transfer pathway and temperature change.
Planned learner game exercise
Select compression and heat-exchange conditions, predict final temperature direction and justify observed data.
Independent practice
Write a bicycle-pump explanation and critique use of pV=constant across unequal temperatures.
Original practice example · Separate Physics Higher
Why can rapid use of a bicycle pump warm its enclosed gas?
Show working and model answer
Working / reasoning
A force does work compressing the gas, transferring energy into its internal energy before it can fully transfer out.
Answer
Work increases internal energy and can increase temperature; pV need not stay constant.
Exit check and success criteria
Causal work → internal energy → temperature explanation and correct rejection of isothermal equation in rapid-heating case.
During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.
Misconceptions, practical links and mastery
Check these misconceptions
Compression always keeps temperature constant; hotter pump proves energy creation.
Practical preparation
Optional teacher-led bicycle-pump demonstration; not an RP.
Virtual preparation and revision only. Required hands-on activities and school records remain separate.
Proposed mastery
0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.