AQA AS Physics Past Papers & Mark Schemes

Physics problems at AS level typically follow a pattern: identify the physical principle, select the correct equation, substitute known values, and solve. The challenge is in the first step — recognising which principle applies. When approaching a mechanics problem, ask: is this about forces (Newton's laws), motion (suvat), energy (conservation of energy), or momentum (conservation of momentum)? Each framework gives you different equations and different starting points. The correct choice often depends on what quantities you know and what you need to find. For suvat problems, list the five quantities (s, u, v, a, t) at the start of every question and tick off which ones you know. You need three known quantities to select the right equation. The most common error is using suvat equations when acceleration is not constant — these equations only work for uniform acceleration. If the question describes a force that changes with time or position, you need a different approach (typically energy methods). Circuit questions test Kirchhoff's laws systematically. For complex circuits, draw the circuit clearly, label all currents with arrows, and apply Kirchhoff's current law (sum of currents into a junction equals sum leaving) and Kirchhoff's voltage law (sum of EMFs around a loop equals sum of p.d.s) to generate simultaneous equations. Internal resistance questions combine these ideas: the terminal p.d. equals EMF minus the 'lost volts' across the internal resistance (V = ε − Ir). Uncertainty calculations appear throughout both papers. For addition and subtraction, add absolute uncertainties. For multiplication and division, add percentage uncertainties. For powers, multiply the percentage uncertainty by the power. Students who practise these rules until they are automatic gain marks that others find difficult — uncertainty questions carry marks at every level of the paper. Particle physics questions often involve conservation laws: conservation of charge, baryon number, lepton number, and strangeness. Before and after a particle interaction, these quantities must balance. Practise identifying each quantity for common particles (proton: charge +1, baryon number +1, lepton number 0, strangeness 0) until you can check conservation by inspection.