What internal energy is, and how the first law of thermodynamics shares energy between raising it and doing work. Play the two simulations below. The gamified lessons and the topic Paper 4 practice are live below too.
Simulations · live
Interactive · liveInternal energy and temperatureInternal energy as the total random energy of the molecules, set by temperature for an ideal gas.Loads only when you launch, so the page stays fast.
Interactive · liveThe first law: ΔU = q + WHeat in, work done by the gas, and the change in internal energy, kept in balance by the first law.Loads only when you launch, so the page stays fast.
Paper 4 practice · live
Structured questions · with worked solutionsTen original Paper 4 style questionsA full topic set on internal energy and the first law, most questions linking the two lessons across a process, with full worked solutions.Open practice →