Syllabus

IB Physics HL Syllabus Overview

This is based on the 2025 syllabus.

Theme	Topic	Level	Key Understanding	Relevant Equations & Data (from Data Booklet)
A. Space, Time and Motion	A.1 Kinematics	SL & HL	Motion analysis using position, displacement, distance, velocity, speed, and acceleration. Difference between instantaneous and average values.	s, u, v, a, t
		SL & HL	Equations for uniformly accelerated motion (SUVA equations).	s = ((u+v)/2)t; v = u + at; s = ut + (1/2)at²; v² = u² + 2as
		SL & HL	Projectile motion in the absence of fluid resistance, resolving motion into horizontal and vertical components.	Use SUVA equations with aₓ=0 and aᵧ=g. g = 9.8 ms⁻²
		SL & HL	Qualitative effect of fluid resistance on projectiles (affecting time of flight, trajectory, range, and terminal speed).	N/A
	A.2 Forces and Momentum	SL & HL	Newton's three laws of motion; representing forces on free-body diagrams to find the resultant force.	F = ma
		SL & HL	Contact forces: Normal force (Fₙ), Friction (static and dynamic), Tension, Hooke's Law (elastic force), Viscous drag, and Buoyancy.	Ff ≤ μsFₙ; Ff = μdFₙ; FH = -kx; Fd = 6πηrv; Fb = ρVg
		SL & HL	Field forces: Gravitational force (weight), Electric force, Magnetic force.	Fg = mg
		SL & HL	Linear momentum and impulse; conservation of linear momentum in the absence of external forces.	p = mv; J = FΔt = Δp
		SL & HL	Newton's second law in terms of momentum (F = Δp/Δt) for situations where mass may change.	F = Δp/Δt
		SL & HL	Elastic and inelastic collisions; explosions and related energy considerations.	N/A
		SL & HL	Centripetal acceleration and the centripetal force required for uniform circular motion.	a = v²/r = ω²r = 4π²r/T²; v = 2πr/T = ωr
	A.3 Work, Energy and Power	SL & HL	Conservation of energy; work as a transfer of energy; Sankey diagrams.	N/A
		SL & HL	Work done by a constant force; work done by a resultant force equals the change in kinetic energy.	W = Fs cosθ
		SL & HL	Mechanical energy (sum of kinetic and potential energies) is conserved in the absence of resistive forces.	Ek = (1/2)mv² = p²/(2m); ΔEp = mgΔh; EH = (1/2)kΔx²
		SL & HL	Power as the rate of energy transfer or work done; efficiency in terms of power or energy.	P = ΔW/Δt = Fv; η = useful work out / total work in = useful power out / total power in
		SL & HL	Energy density of fuel sources.	N/A
	A.4 Rigid Body Mechanics	HL Only	Torque of a force about an axis.	τ = Fr sinθ
		HL Only	Rotational equilibrium occurs when the resultant torque is zero.	Στ = 0
		HL Only	Rotational motion described by angular displacement (Δθ), velocity (ω), and acceleration (α).	Δθ = ((ωf + ωi)/2)t; ωf = ωi + αt; Δθ = ωit + (1/2)αt²; ωf² = ωi² + 2αΔθ
		HL Only	Moment of inertia (I) and its dependence on mass distribution.	I = Σmr²
		HL Only	Newton's second law for rotation; angular momentum (L) and its conservation.	τ = Iα; L = Iω; ΔL = τΔt = Δ(Iω)
		HL Only	Rotational kinetic energy.	Ek = (1/2)Iω² = L²/(2I)
	A.5 Galilean and Special Relativity	HL Only	Galilean relativity: Newton's laws are the same in all inertial reference frames.	x' = x - vt; t' = t; u' = u - v
		HL Only	The two postulates of special relativity.	1. The laws of physics are the same for all inertial observers. 2. The speed of light in a vacuum is the same for all inertial observers (c = 3.00 x 10⁸ ms⁻¹).
		HL Only	Lorentz transformations and the Lorentz factor (γ).	x' = γ(x-vt); t' = γ(t - vx/c²); γ = 1 / √(1 - v²/c²)
		HL Only	Relativistic velocity addition.	u' = (u-v) / (1 - uv/c²)
		HL Only	Time dilation and proper time (Δt₀); length contraction and proper length (L₀).	Δt = γΔt₀; L = L₀/γ
		HL Only	Space-time diagrams (Minkowski diagrams), world lines, and the invariance of the space-time interval (Δs).	(Δs)² = (cΔt)² - (Δx)²; tanθ = v/c
B. The Particulate Nature of Matter	B.1 Thermal Energy Transfers	SL & HL	Molecular theory of solids, liquids, and gases; Kelvin and Celsius scales.	Temperature (K) = temperature (°C) + 273
		SL & HL	Internal energy as the sum of random kinetic and intermolecular potential energies. Average kinetic energy is proportional to absolute temperature.	Ek = (3/2)kBT; kB = 1.38 x 10⁻²³ JK⁻¹
		SL & HL	Heat transfer (conduction, convection, radiation) and phase changes (specific heat capacity and specific latent heat).	Q = mcΔT; Q = mL; ΔQ/Δt = kA(ΔT/Δx)
		SL & HL	Thermal radiation from a black body: Stefan-Boltzmann law, luminosity, and apparent brightness.	L = σAT⁴; σ = 5.67 x 10⁻⁸ Wm⁻²K⁻⁴; b = L/(4πd²)
		SL & HL	Wien's displacement law for peak wavelength emission.	λₘₐₓT = 2.9 x 10⁻³ mK
	B.2 Greenhouse Effect	SL & HL	Conservation of energy, emissivity, and albedo in the context of planetary energy balance.	emissivity = power radiated per unit area / σT⁴; albedo = total scattered power / total incident power
		SL & HL	The solar constant (S) and its role in determining Earth's average temperature.	S = 1.36 x 10³ Wm⁻²
		SL & HL	Main greenhouse gases (CH₄, H₂O, CO₂, N₂O) and their absorption of infrared radiation.	N/A
	B.3 Gas Laws	SL & HL	Ideal gas model and the kinetic theory of gases.	N/A
		SL & HL	Ideal Gas Law and its relation to empirical gas laws.	PV = nRT = NkBT; R = 8.31 JK⁻¹mol⁻¹; NA = 6.02 x 10²³ mol⁻¹
		SL & HL	Relationship between pressure and average translational kinetic energy of molecules.	P = (1/3)ρ<v²>
		SL & HL	Internal energy of a monatomic ideal gas.	U = (3/2)nRT = (3/2)NkBT
	B.4 Thermodynamics	HL Only	The first law of thermodynamics: conservation of energy for a closed system.	Q = ΔU + W
		HL Only	Work done by or on a gas during volume changes.	W = PΔV
		HL Only	Change in internal energy of a system is related to its temperature change.	ΔU = (3/2)nRΔT = (3/2)NkBT
		HL Only	Entropy (S) as a measure of disorder, related to macroscopic quantities and microscopic states.	ΔS = ΔQ/T; S = kB lnΩ
		HL Only	The second law of thermodynamics: the entropy of an isolated system always increases.	N/A
		HL Only	Thermodynamic processes: isovolumetric, isobaric, isothermal, and adiabatic.	For monatomic ideal gas: PV^(5/3) = constant (adiabatic)
		HL Only	Heat engines, their efficiency, and the Carnot cycle as a theoretical limit.	η = useful work / input energy; η_Carnot = 1 - Tc/Th
	B.5 Current and Circuits	SL & HL	EMF (ε), internal resistance (r), Ohm's Law, and resistivity (ρ).	ε = I(R+r); R = V/I; ρ = RA/L
		SL & HL	Electric current as flow of charge; potential difference as work done per unit charge.	I = Δq/Δt; V = W/q
		SL & HL	Electrical power dissipation in a resistor.	P = IV = I²R = V²/R
		SL & HL	Resistors in series and parallel.	Rs = R₁ + R₂ + ...; 1/Rp = 1/R₁ + 1/R₂ + ...
C. Wave Behaviour	C.1 Simple Harmonic Motion (SHM)	SL & HL	Defining equation of SHM and its link to period, frequency, and angular frequency.	a = -ω²x; T = 1/f = 2π/ω
		SL & HL	Period of a mass-spring system and a simple pendulum.	T = 2π√(m/k); T = 2π√(l/g)
		HL Only	Equations for displacement, velocity, and energy in SHM, including phase angle (φ).	x = x₀sin(ωt+φ); v = ωx₀cos(ωt+φ); v = ±ω√(x₀²-x²); ET = (1/2)mω²x₀²; Ep = (1/2)mω²x²
	C.2 Wave Model	SL & HL	Transverse and longitudinal waves; relationship between wave speed, frequency, and wavelength.	v = fλ
		SL & HL	Nature of sound and electromagnetic waves.	Electromagnetic spectrum wavelengths provided in data booklet.
	C.3 Wave Phenomena	SL & HL	Wavefronts, rays, reflection, refraction, and Snell's Law.	n₁/n₂ = sinθ₂/sinθ₁ = v₂/v₁
		SL & HL	Superposition, coherence, and constructive/destructive interference conditions.	Path difference = nλ (constructive); Path difference = (n+1/2)λ (destructive)
		SL & HL	Young's double-slit experiment.	s = λD/d
		HL Only	Single-slit diffraction and its intensity pattern.	θ = λ/b (position of first minimum)
		HL Only	Interference from multiple slits and diffraction gratings.	nλ = d sinθ
	C.4 Standing Waves and Resonance	SL & HL	Formation of standing waves from superposition; nodes and antinodes.	N/A
		SL & HL	Standing wave patterns in strings and pipes.	N/A
		SL & HL	Resonance, natural frequency, driving frequency, and the effect of damping.	N/A
	C.5 Doppler Effect	SL & HL	Doppler effect for sound and electromagnetic waves.	For light: Δf/f ≈ Δλ/λ ≈ v/c
		HL Only	Equations for moving source and moving observer for sound waves.	f' = f(v/(v±us)); f' = f((v±u₀)/v)
D. Fields	D.1 Gravitational Fields	SL & HL	Newton's universal law of gravitation; gravitational field strength (g).	F = G(m₁m₂/r²); g = G(M/r²); G = 6.67 x 10⁻¹¹ Nm²kg⁻²
		HL Only	Gravitational potential energy (Ep) and gravitational potential (Vg).	Ep = -G(m₁m₂/r); Vg = -G(M/r)
		HL Only	Work done moving a mass; relationship between field strength and potential gradient.	W = mΔVg; g = -ΔVg/Δr
		HL Only	Orbital speed and escape speed.	vorbital = √(GM/r); vesc = √(2GM/r)
	D.2 Electric and Magnetic Fields	SL & HL	Coulomb's Law; electric field strength (E).	F = k(q₁q₂/r²); E = F/q; k = 8.99 x 10⁹ Nm²C⁻² = 1/(4πε₀); ε₀ = 8.85 x 10⁻¹² C²N⁻¹m⁻²
		SL & HL	Uniform electric field between parallel plates.	E = V/d
		HL Only	Electric potential energy (Ep) and electric potential (Ve).	Ep = k(q₁q₂/r); Ve = k(Q/r)
		HL Only	Work done moving a charge; relationship between field strength and potential gradient.	W = qΔVe; E = -ΔVe/Δr
	D.3 Motion in Electromagnetic Fields	SL & HL	Force on a moving charge in a magnetic field.	F = qvB sinθ
		SL & HL	Force on a current-carrying conductor in a magnetic field.	F = BIL sinθ
		SL & HL	Force per unit length between two parallel current-carrying wires.	F/L = μ₀(I₁I₂)/(2πr); μ₀ = 4π x 10⁻⁷ TmA⁻¹
	D.4 Induction	HL Only	Magnetic flux (Φ) and Faraday's Law of induction; Lenz's Law.	Φ = BA cosθ; ε = -N(ΔΦ/Δt)
		HL Only	Motional EMF induced in a straight conductor.	ε = BvL
E. Nuclear and Quantum Physics	E.1 Structure of the Atom	SL & HL	Geiger-Marsden experiment and the discovery of the nucleus.	N/A
		SL & HL	Emission and absorption spectra as evidence for discrete atomic energy levels.	E = hf; h = 6.63 x 10⁻³⁴ Js
		HL Only	Relationship between nuclear radius (R) and nucleon number (A).	R = R₀A^(1/3); R₀ = 1.20 x 10⁻¹⁵ m
		HL Only	Bohr model for hydrogen: discrete energy levels and quantization of angular momentum.	E = -13.6/n² eV; mvr = nh/(2π)
	E.2 Quantum Physics	HL Only	Photoelectric effect as evidence of the particle nature of light.	Emax = hf - Φ
		HL Only	De Broglie wavelength as evidence of the wave nature of matter.	λ = h/p
		HL Only	Compton scattering and the change in photon wavelength.	Δλ = λ' - λ = (h/mₑc)(1-cosθ)
	E.3 Radioactive Decay	SL & HL	Isotopes, binding energy, mass defect, and mass-energy equivalence.	E = mc²
		SL & HL	Random and spontaneous nature of radioactive decay (α, β⁻, β⁺, γ).	N/A
		SL & HL	Activity, count rate, and half-life.	N/A
		HL Only	The decay constant (λ) and the radioactive decay law.	N = N₀e^(-λt); A = λN = λN₀e^(-λt); T½ = ln(2)/λ
	E.4 Fission	SL & HL	Spontaneous and neutron-induced fission; chain reactions.	N/A
		SL & HL	Role of components in a nuclear power plant (moderator, control rods, heat exchanger).	N/A
	E.5 Fusion and Stars	SL & HL	Fusion as the energy source of stars; conditions for fusion (high density and temperature).	N/A
		SL & HL	Stellar equilibrium (radiation pressure vs. gravitational forces).	N/A
		SL & HL	Hertzsprung-Russell (HR) diagram and main stellar regions.	N/A
		SL & HL	Stellar parallax method for determining distance to stars.	d(parsec) = 1 / p(arc-second)

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Topic Breakdown by Theme

Theme A: Space, Time and Motion (Core)

This is the foundation of the entire course. It covers classical mechanics from kinematics through to work, energy, and power, then extends into rigid body mechanics and relativity at HL.

Key concepts by subtopic:

• A.1 Kinematics: Describing motion using displacement, velocity, and acceleration. The SUVA equations are the most important tool — memorise them and practise identifying which variable is unknown in each problem. Projectile motion is a frequent exam question; always resolve into horizontal and vertical components independently.
• A.2 Forces and Momentum: Free-body diagrams are essential. Newton's second law in momentum form ($F = \Delta p / \Delta t$) is commonly tested with impulse questions. Elastic vs inelastic collisions — remember that kinetic energy is conserved in elastic collisions only.
• A.3 Work, Energy and Power: The work-energy theorem connects force and motion through energy. Efficiency questions are straightforward marks — do not lose them.
• A.4 Rigid Body Mechanics (HL): Torque and rotational equilibrium appear frequently in Paper 2. The moment of inertia depends on mass distribution, not just total mass.
• A.5 Relativity (HL): Time dilation and length contraction are the most commonly tested concepts. Always identify the proper time and proper length first — these belong to the frame where the event occurs at the same position (proper time) or where the object is at rest (proper length).

Theme B: The Particulate Nature of Matter (Core)

This theme bridges mechanics and thermal physics.

• B.1 Thermal Energy Transfers: The distinction between specific heat capacity and specific latent heat is critical. Heat transfer mechanisms (conduction, convection, radiation) are qualitative but commonly tested.
• B.2 Greenhouse Effect: Energy balance of the Earth is a popular exam topic. Be comfortable with albedo, emissivity, and the solar constant.
• B.3 Gas Laws: The ideal gas law connects macroscopic quantities (P, V, T) to microscopic properties (N, $k_B$). The derivation of $P = \frac{1}{3}\rho \langle v^2 \rangle$ from kinetic theory is a classic HL derivation.
• B.4 Thermodynamics (HL): The first law ($\Delta U = Q - W$) and second law (entropy) are central. Be able to sketch and interpret PV diagrams for all four thermodynamic processes.
• B.5 Current and Circuits: Internal resistance questions are almost guaranteed. Always draw the circuit diagram first.

Theme C: Wave Behaviour (Core)

Waves appear across many contexts — from sound and light to quantum mechanics.

• C.1 SHM: The defining equation $a = -\omega^2 x$ is fundamental. Energy interchange between kinetic and potential in SHM mirrors that of a mass-spring system.
• C.2 Wave Model: Know the full electromagnetic spectrum in order. The wave equation $v = f\lambda$ is used in almost every wave problem.
• C.3 Wave Phenomena: Snell's law, Young's double slit, and single-slit diffraction are heavily examined. For double slit: $s = \lambda D / d$.
• C.4 Standing Waves and Resonance: Know the harmonic series for both open and closed pipes, and for strings fixed at both ends.
• C.5 Doppler Effect: The electromagnetic Doppler effect ($\Delta f / f \approx v / c$) is used in astrophysics. The full sound Doppler equations (HL) require careful attention to signs.

Theme D: Fields (Core)

Fields describe forces that act at a distance — gravitational, electric, and magnetic.

• D.1 Gravitational Fields: Orbital mechanics (Kepler's laws, orbital speed, escape velocity) are common. Remember that gravitational potential energy is negative.
• D.2 Electric and Magnetic Fields: Coulomb's law parallels Newton's law of gravitation. Electric potential and field strength are related by $E = -\Delta V_e / \Delta r$.
• D.3 Motion in Electromagnetic Fields: The force on a charge in a magnetic field ($F = qvB \sin\theta$) is always perpendicular to the velocity, causing circular motion. The velocity selector and mass spectrometer are classic applications.
• D.4 Induction (HL): Faraday's law ($\varepsilon = -N \Delta\Phi / \Delta t$) and Lenz's law (direction of induced current opposes the change) are essential.

Theme E: Nuclear and Quantum Physics (Core)

This theme introduces the quantum nature of matter and energy.

• E.1 Structure of the Atom: The Geiger-Marsden experiment, emission/absorption spectra, and the Bohr model for hydrogen are all exam staples.
• E.2 Quantum Physics (HL): The photoelectric effect ($E_{max} = hf - \Phi$) and de Broglie wavelength ($\lambda = h/p$) demonstrate wave-particle duality.
• E.3 Radioactive Decay: Half-life, activity, and the decay law ($N = N_0 e^{-\lambda t}$) are SL essentials. Mass defect and binding energy connect to $E = mc^2$.
• E.4 Fission: Chain reactions, critical mass, and the role of moderators and control rods.
• E.5 Fusion and Stars: The HR diagram, stellar evolution, and the conditions for fusion (high temperature and density).

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Assessment Structure

Standard Level (SL)

Component	Paper 1	Paper 2	IA
Duration	45 min (MCQ) + 75 min (structured)	75 min	—
Weighting	30% (MCQ) + 20% (structured) = 50%	25%	25%

Higher Level (HL)

Component	Paper 1	Paper 2	Paper 3	IA
Duration	60 min (MCQ) + 90 min (structured)	90 min	60 min	—
Weighting	36% (MCQ) + 24% (structured) = 60%	20%	20%	20%

Paper 1 consists of multiple-choice questions (Section A) followed by structured/data-based questions (Section B). No calculator is permitted for Section A; a calculator is permitted for Section B.

Paper 2 contains short-response and extended-response questions covering the full syllabus. A calculator is required.

Paper 3 (HL only) focuses on the HL extension material and requires problem-solving and analytical skills.

IA (Internal Assessment) is an individual investigation of your own choosing. It is worth 20% at both SL and HL.

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Recommended Study Approach

1. Build a Strong Foundation in Mechanics

Theme A (Space, Time and Motion) underpins almost everything else. If your mechanics is weak, fields, waves, and thermodynamics will all be harder. Master SUVA equations, free-body diagrams, and energy conservation before moving on.

2. Practise Derivations (HL)

HL exams frequently require you to derive results from first principles. Key derivations to know:

• Centripetal acceleration from circular motion geometry
• Pressure of an ideal gas from kinetic theory
• Gravitational potential energy from Newton's law of gravitation
• Escape velocity from energy conservation
• Bohr model energy levels

3. Use the Data Booklet Effectively

The IB Physics data booklet contains all the formulae you need. However, you must know:

• What each symbol means
• The conditions under which each formula applies
• How to combine formulae to solve multi-step problems

4. Focus on Multi-Step Problems

Examination questions increasingly combine concepts from different themes. For example, a question might combine:

• Projectile motion (A.1) with gravitational fields (D.1)
• Electric fields (D.2) with energy conservation (A.3)
• Nuclear decay (E.3) with thermodynamics (B.4)

5. Exam Technique

• Show all working: Marks are awarded for method, not just the final answer.
• Include units in every intermediate step: A correct numerical answer without units loses marks.
• Draw diagrams: Free-body diagrams, circuit diagrams, and ray diagrams earn marks and help you organise your thinking.
• Estimate before calculating: Quick order-of-magnitude estimates catch calculation errors.
• Manage your time: In Papers 1 and 2, allocate roughly 1 mark per minute. Do not get stuck on a single question.

6. Common Pitfalls

• Confusing distance and displacement, or speed and velocity.
• Forgetting the negative sign in the first law of thermodynamics sign convention.
• Using $\theta = 0$ instead of $\theta = 90^\circ$ for the angle between velocity and magnetic field when applying $F = qvB \sin\theta$.
• Mixing up half-life and decay constant — remember $T_{1/2} = \ln 2 / \lambda$.
• Forgetting that gravitational potential energy is negative and approaches zero at infinity.