The caloric and kinetic theories of heat, Rumford’s and Joule’s evidence, temperature and the kinetic energy of molecules, and how the kinetic theory explains solids, liquids and gases.
5 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
Rumford noticed that boring a cannon made endless heat. If heat were a fluid that could run out, that should not happen. His observation changed physics.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Heat the gas and watch the particles speed up and hit the walls harder.
Copy these into your notebook in your own words — that is how they stick.
Heat is an invisible fluid that cannot be created; discarded.
Heat is the energy of the motion of particles.
Boring a cannon produced heat continuously: evidence against caloric theory.
Falling weights turned paddles; work done = heat gained; conservation of energy.
Regular, very close, vibrate; fixed shape and volume.
Close, random, slide past; fixed volume, no fixed shape.
Far apart, fast, random; no fixed shape or volume.
Proportional to the average kinetic energy of molecules; thermal energy flows hot → cold.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness. More games in the Physics Arcade.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better. Work each item on paper first.
Write full answers, then reveal the mark scheme and tick the points you earned (15 marks in total). Show all your working — method marks count. Your answers are saved on this device.
Question 1 [15 marks]
A sealed syringe contains a small amount of a gas. The plunger is pushed in.
(a) (a) Describe the arrangement and motion of the particles in a gas. [3]
(b) (b) Use the kinetic theory to explain why the gas is easily compressed but a liquid is not. [2]
(c) (c) Explain how the gas exerts a pressure on the wall of the syringe. [3]
(d) (d) State how the average kinetic energy of the gas molecules changes if the gas is heated. [1]
(e) (e) Describe Rumford’s observation and why it counted against the caloric theory. [3]
(f) (f) State what Joule’s paddle-wheel experiment showed. [3]
Find these in your own past-paper booklets for extra timed practice. Items above are written in the style of these papers; any adapted from a specific question say so.