IB Physics Notes (SL & HL)

The new IB Physics course (first exams 2025) is organised in five themes, A to E, with topic codes such as A.1 Kinematics and D.2 Electric and magnetic fields. These notes follow that structure exactly, so you can find any topic by its code. SL and HL are in one note, with additional higher level content tagged HL ONLY. Each note tags the equations given in the data booklet, works through exam-style examples step by step and builds the data skills tested in Paper 1B: graphs, gradients, uncertainties and error bars.

What every note gives you

• New syllabus only. Topic codes A.1 to E.5, matching the guide for first exams 2025.
• SL and HL in one note, with additional HL content tagged HL ONLY.
• Data booklet tags, so you know which equations are given and which ideas you must explain in words.
• Paper 1B data skills: linearising graphs, gradients and uncertainties, built into every topic.
• Worked examples step by step, with units and significant figures handled the way examiners expect.
• Linking questions and IA ideas, because the new course tests how topics connect.

Notes ready now

1. A.1A.1 KinematicsDistance and displacement, speed, velocity and acceleration, motion graphs, the suvat equations, free fall, projectiles launched at any angle, the qualitative effect of air resistance, and the Paper 1B graph skills behind measuring g.~15 min read · SL + HL
2. A.2A.2 Forces and momentumNewton's three laws, free-body diagrams, every contact and field force (friction, Hooke's law, Stokes drag, buoyancy), momentum, impulse, collisions and explosions, and circular motion.~12 min read · SL + HL
3. A.3A.3 Work, energy and powerWork as energy transfer, kinetic, gravitational and elastic potential energy, conservation of mechanical energy, Sankey diagrams, power P = Fv, efficiency and the energy density of fuels.~7 min read · SL + HL
4. A.4A.4 Rigid body mechanicsTorque and rotational equilibrium, angular displacement, velocity and acceleration, the rotational suvat equations, moment of inertia, Newton's second law for rotation, angular momentum and rotational kinetic energy.~9 min read · HL
5. A.5A.5 Galilean and special relativityReference frames and Galilean transformations, Einstein's two postulates, the Lorentz transformations, time dilation, length contraction, simultaneity, the spacetime interval, spacetime diagrams and the muon experiment.~8 min read · HL
6. B.1B.1 Thermal energy transfersThe particle model, density, Kelvin temperature and internal energy, specific heat capacity and latent heat, conduction, convection and radiation, the Stefan–Boltzmann law, luminosity, apparent brightness and Wien's law.~8 min read · SL + HL
7. B.2B.2 Greenhouse effectEmissivity and albedo, the solar constant and the factor of four, a simple energy-balance model of the Earth, greenhouse gases and their sources, why molecules absorb infrared, and the enhanced greenhouse effect.~6 min read · SL + HL
8. B.3B.3 Gas lawsPressure, the mole and Avogadro's number, the three gas laws and the ideal gas equation in moles and molecules, the kinetic model of an ideal gas, P = ⅓ρv², the internal energy of a monatomic gas, and when real gases are not ideal.~7 min read · SL + HL
9. B.4B.4 ThermodynamicsThe first law Q = ΔU + W, work done by a gas, isobaric, isovolumetric, isothermal and adiabatic processes on P–V diagrams, cycles and heat engines, entropy, the second law and the Carnot limit.~8 min read · HL
10. B.5B.5 Current and circuitsCharge and current, potential difference, resistance and resistivity, Ohm's law and I–V graphs, electrical power, series and parallel circuits, potential dividers, emf and internal resistance.~8 min read · SL + HL
11. C.1C.1 Simple harmonic motionThe conditions for SHM and a = −ω²x, period, frequency and angular frequency, the mass–spring system and the simple pendulum, energy changes, and (HL) phase angle, the x, v and energy equations.~6 min read · SL + HL
12. C.2C.2 Wave modelTransverse and longitudinal travelling waves, wavelength, frequency, period and wave speed, displacement–distance and displacement–time graphs, sound waves, the electromagnetic spectrum, and mechanical versus electromagnetic waves.~6 min read · SL + HL
13. C.3C.3 Wave phenomenaWavefronts and rays, reflection, refraction and Snell's law, critical angle and total internal reflection, diffraction, superposition and interference, Young's double slit, and (HL) single-slit diffraction and diffraction gratings.~7 min read · SL + HL
14. C.4C.4 Standing waves and resonanceHow standing waves form, nodes and antinodes, harmonics on strings and in open and closed pipes, natural and driving frequency, resonance, and light, critical and heavy damping.~5 min read · SL + HL
15. C.5C.5 Doppler effectThe Doppler effect for sound and light, wavefront diagrams for a moving source, redshift and blueshift of spectral lines as evidence for moving stars and galaxies, and (HL) the moving-source and moving-observer equations for sound.~5 min read · SL + HL
16. D.1D.1 Gravitational fieldsKepler's three laws, Newton's law of gravitation, gravitational field strength and field lines, orbits, and (HL) gravitational potential and potential energy, equipotentials, escape speed, orbital speed and energy.~7 min read · SL + HL
17. D.2D.2 Electric and magnetic fieldsCharge and its conservation, charging by friction, contact and induction, Coulomb's law, electric field strength and field lines, the uniform field between plates, Millikan's experiment, magnetic field patterns, and (HL) electric potential and equipotentials.~7 min read · SL + HL
18. D.3D.3 Motion in electromagnetic fieldsCharged particles in uniform electric fields (parabolic paths), in uniform magnetic fields (circles), in crossed fields (velocity selectors), the force on a current-carrying wire, and the force between parallel wires.~6 min read · SL + HL
19. D.4D.4 InductionMagnetic flux and flux linkage, Faraday's law, the emf in a moving conductor, Lenz's law and conservation of energy, and the sinusoidal emf from a coil rotating in a magnetic field.~6 min read · HL
20. E.1E.1 Structure of the atomThe Geiger–Marsden–Rutherford experiment, nuclear notation, emission and absorption spectra, discrete energy levels and photons, and (HL) nuclear radius and density, distance of closest approach and the Bohr model of hydrogen.~6 min read · SL + HL
21. E.2E.2 Quantum physicsThe photon model of light, the photoelectric effect and Einstein's equation, threshold frequency and work function, de Broglie wavelength and electron diffraction, photon momentum and Compton scattering.~6 min read · HL
22. E.3E.3 Radioactive decayIsotopes and nuclear stability, the strong force, mass defect and binding energy, the binding-energy-per-nucleon curve, alpha, beta and gamma decay, neutrinos, half-life and activity, background radiation, and (HL) the decay constant and exponential decay.~7 min read · SL + HL
23. E.4E.4 FissionSpontaneous and neutron-induced fission, the energy released, chain reactions and critical mass, the parts of a nuclear power station (fuel, moderator, control rods, coolant, heat exchanger, shielding), and nuclear waste.~5 min read · SL + HL
24. E.5E.5 Fusion and starsFusion and the conditions it needs, stellar equilibrium, the energy source of stars, stellar parallax, the Hertzsprung–Russell diagram, and the evolution of stars into white dwarfs, neutron stars and black holes.~6 min read · SL + HL

Exam special notes

Built from the IB examiners' subject reports: where students actually lose marks, and how to stop it.

1. ★IB Physics Grade Boundaries (May 2025, new syllabus)Every grade boundary for IB Physics from the IB subject reports: May 2025 time zones 1–3 (first new-syllabus session) and November 2024, SL and HL, overall and paper by paper.~5 min read · Grade boundaries
2. ★IB Physics Paper 1A: Multiple-Choice Strategies and TrapsHow to attack IB Physics Paper 1A multiple choice: timing with Paper 1B, the shortcuts examiners recommend, worked examples and a bank of the misconceptions flagged in the 2024–25 subject reports.~9 min read · Paper 1A strategy
3. ★IB Physics Paper 1B: Data, Uncertainties and Graph SkillsEverything Paper 1B tests in IB Physics: recording uncertainties, propagating them, max and min gradient lines, linearising graphs, units of gradients and evaluating experiments, with the errors examiners flagged.~8 min read · Paper 1B skills
4. ★IB Physics Paper 2: How to Write Full-Mark AnswersHow to write IB Physics Paper 2 answers that earn every mark: setting out calculations, "show that" questions, model answers for the "explain" questions examiners see go wrong, and how to tackle the long multi-concept questions.~8 min read · Paper 2 answers
5. ★IB Physics IA Guide: Scientific Investigation (New Syllabus)A practical guide to the new-syllabus IB Physics internal assessment: what each of the four criteria rewards, how to write a focused research question, the uncertainty analysis moderators expect and how to write a conclusion and evaluation that score.~7 min read · IA guide
6. ★IB Physics Data Booklet: Equations Not Given and How to Use ItWhat the IB Physics data booklet (first assessment 2025) contains, the equations and facts it leaves out that you must know or derive, and how to use the booklet quickly in Papers 1 and 2.~8 min read · Data booklet guide
7. ★IB Physics Command Terms and How Markschemes Award MarksWhat every IB Physics command term asks for, and how Paper 2 markschemes award marks: marking points, "max" totals, alternative answers, essential words, OWTTE, error carried forward and the rules on units and significant figures.~7 min read · Command terms & marks

Full syllabus map

Practise any topic with full mark schemes in the free IB Paper Generator.

Frequently asked questions