Physics › Equations

A-level physics equations by unit

Browse every equation used in the lessons, grouped by unit and linked to its source lesson. Where an equation's scope is easy to misread, the entry states the conditions under which it applies.

The marks refer to the AQA 7408 data booklet. An equation it prints is marked as such, and one it leaves out is marked to learn. An equation with no mark has not been checked against that booklet, and some of these belong to the Edexcel, OCR or CIE specification rather than AQA’s, so check them against your own board’s data or formula booklet.

AQA publishes the booklet itself as a PDF: AQA A-level Physics data and formulae (7408).

All 34 equations the booklet leaves out, across every unit, are on the equations to memorise; any one candidate needs 22 to 25 of them, depending on the option.

The units

Which lesson states it

Every lesson in the library that puts an equation on the page, under the unit holding it. If you know roughly what the equation is about but not where it lives, this is the way in; if you know what it looks like but not what it is called, the search box holds all 214 of them by their own symbols.

• Uncertainty and errorMeasurements1 equation, 1 to learn
• Moments and equilibriumMechanics1 equation
• Motion graphs and the SUVAT equationsMechanics5 equations
• Newton's laws and the resultant forceMechanics1 equation
• Mass and weightMechanics1 equation, 1 to learn
• Momentum and impulseMechanics4 equations, 1 to learn
• Work, energy and powerMechanics3 equations
• Conservation of energyMechanics2 equations
• Density and Hooke's lawMaterials3 equations
• Stress, strain and the Young modulusMaterials3 equations
• Fluids: pressure, upthrust and viscosityMaterials4 equations
• Progressive wavesWaves3 equations, 1 to learn
• Polarisation and electromagnetic wavesWaves1 equation
• Stationary waves on stringsWaves3 equations, 1 to learn
• Stationary waves in air columnsWaves3 equations
• Refraction and Snell's lawWaves3 equations
• Total internal reflection and optical fibresWaves1 equation
• Interference and Young's double slitWaves3 equations, 2 to learn
• Diffraction gratingsWaves2 equations, 1 to learn
• Lenses and imagesWaves3 equations
• The photoelectric effect and the photonQuantum phenomena1 equation
• Energy levels and photon emissionQuantum phenomena1 equation
• Wave-particle dualityQuantum phenomena1 equation
• Constituents of the atomParticles1 equation, 1 to learn
• Antimatter and photonsParticles1 equation
• Current, charge and potential differenceElectricity2 equations
• Charge carriers, drift speed and resistanceElectricity2 equations
• Resistivity and temperatureElectricity1 equation
• Series, parallel and powerElectricity4 equations, 1 to learn
• The potential divider and its outputElectricity2 equations, 1 to learn
• Sensing circuits and the potentiometerElectricity1 equation
• EMF and internal resistanceElectricity2 equations
• Circular motionPeriodic motion4 equations
• Simple harmonic motionPeriodic motion3 equations
• The mass on a spring and the simple pendulumPeriodic motion2 equations
• Energy in an oscillation and dampingPeriodic motion2 equations
• Specific heat capacity and latent heatThermal physics3 equations
• Ideal gases and the gas lawsThermal physics3 equations, 1 to learn
• The kinetic theory model and its derivationThermal physics1 equation
• What temperature means for a gasThermal physics1 equation
• Newton's law of gravitationGravitational fields3 equations
• Gravitational potentialGravitational fields3 equations
• Orbits and satellitesGravitational fields4 equations, 3 to learn
• Coulomb's law and electric field strengthElectric fields4 equations
• Electric potentialElectric fields3 equations
• Capacitors and the dielectricCapacitance3 equations
• Energy stored and capacitor combinationsCapacitance3 equations
• The time constant and exponential decayCapacitance3 equations, 1 to learn
• Magnetic flux density and the force on a wireMagnetic fields2 equations
• Force on a moving chargeMagnetic fields4 equations, 1 to learn
• Magnetic flux and flux linkageMagnetic fields2 equations
• Electromagnetic induction: Faraday and LenzMagnetic fields2 equations
• Alternating currentsMagnetic fields2 equations
• TransformersMagnetic fields2 equations
• Alpha, beta and gamma radiationNuclear physics1 equation
• Radioactive decay and the decay constantNuclear physics5 equations, 1 to learn
• Nuclear radius and densityNuclear physics3 equations, 2 to learn
• Mass-energy and binding energyNuclear physics1 equation
• Nuclear reactors and safetyNuclear physics1 equation, 1 to learn
• Zener diodes and semiconductor sensorsElectronics1 equation, 1 to learn
• Tuned circuits and the Q factorElectronics2 equations
• Band-pass, band-stop and RC filtersElectronics1 equation, 1 to learn
• The ideal op-amp and the comparatorElectronics1 equation
• Negative feedback amplifiersElectronics3 equations, 1 to learn
• Summing and difference amplifiersElectronics2 equations
• Flip-flops, counters and clocksElectronics1 equation, 1 to learn
• Modulation and PCMElectronics2 equations
• Rotational motion and the angular equationsEngineering physics5 equations, 1 to learn
• Moment of inertia and rotational kinetic energyEngineering physics2 equations
• Torque and angular accelerationEngineering physics2 equations
• Angular momentum and rotational powerEngineering physics4 equations
• The first law and its sign conventionEngineering physics2 equations
• Non-flow processes and p-V diagramsEngineering physics2 equations
• Heat engines and their efficiencyEngineering physics6 equations
• Heat pumps and combined heat and powerEngineering physics2 equations
• The astronomical refracting telescopeAstrophysics1 equation
• Resolving power, collecting power and the CCDAstrophysics2 equations, 1 to learn
• The apparent magnitude scaleAstrophysics1 equation, 1 to learn
• Stellar distances and absolute magnitudeAstrophysics2 equations
• Black-body radiation and spectral classesAstrophysics2 equations
• Supernovae, neutron stars and black holesAstrophysics1 equation
• The Doppler effect and red shiftAstrophysics3 equations, 1 to learn
• Hubble's law and the Big BangAstrophysics1 equation
• Cathode rays and the electron gunTurning points1 equation
• Millikan's oil drop experimentTurning points2 equations
• Electromagnetic waves and the speed of lightTurning points1 equation
• Matter waves and electron microscopesTurning points2 equations
• Time dilation and muon decayTurning points1 equation
• Length contraction, mass and energyTurning points3 equations, 1 to learn
• Ultrasound imagingMedical physics5 equations, 1 to learn
• The physics of diagnostic X-raysMedical physics3 equations, 1 to learn
• The eye as an optical systemMedical physics3 equations
• Intensity, loudness and the decibel scaleMedical physics3 equations, 2 to learn

214 equations across 19 units, 34 of them off the AQA data booklet. See also key ideas, command words and the revision checklist.