HSC Physics Study Guide: From Kinematics to Quantum Physics in NSW

HSC Physics is one of the most demanding of the NSW Higher School Certificate science courses — it requires both deep conceptual understanding of abstract physical principles and the ability to apply quantitative methods (calculation, data analysis, graphing) to novel problems under exam conditions.

The students who achieve Band 5 and Band 6 results are not those who have memorised the most facts. They are those who understand the physical reasoning deeply enough to apply it to unfamiliar scenarios, and who have practised the specific skills the HSC exam tests: Working Scientifically analysis, extended response prose writing, and multi-step calculations.

Advanced Mechanics (Module 5)

Kinematics review and projectile motion: Horizontal motion is constant velocity; vertical motion is constant acceleration (g = 9.8 m/s² downward). The two motions are independent — solve each separately using the SUVAT equations for the vertical component. Key: the time of flight is determined by the vertical motion; the horizontal range follows from t × v_horizontal.

Circular motion: An object in circular motion accelerates toward the centre of the circle (centripetal acceleration a = v²/r = ω²r). This centripetal acceleration is provided by the net inward force — tension for a pendulum, normal force + gravity for a car on a banked curve, gravity for orbital motion. Students consistently confuse centripetal force (the net inward force) with a centrifugal force (a fictitious outward force in a rotating reference frame — not relevant here).

Gravitational fields: Gravitational field strength g = GM/r² (not constant — decreases with distance from the centre). Gravitational potential energy U = −GMm/r (negative because energy must be added to lift an object — the energy is less negative, i.e., greater, at larger r). Escape velocity: set KE = −U: ½mv² = GMm/r → v_esc = √(2GM/r).

Orbital mechanics: For circular orbits, gravitational force provides centripetal force: GMm/r² = mv²/r → v_orbital = √(GM/r). Kepler's Third Law: T² ∝ r³ (T²/r³ = constant for all objects orbiting the same central mass). This law connects orbital period and radius — know how to use it to find either.

Electromagnetism (Module 6)

Electric fields: Electric field strength E = F/q = kq/r² (point charge). Uniform fields between parallel plates: E = V/d. Force on charge: F = qE. Know how to draw field lines and equipotential surfaces for various charge configurations.

Magnetic force on moving charges: F = qvB sinθ. Direction: use the right-hand rule (for positive charges). For current-carrying conductors: F = BIl sinθ. The cross product of velocity/current direction and field direction gives force direction.

Electromagnetic induction (Faraday's Law): EMF = −ΔΦ/Δt where Φ = BAcosθ is magnetic flux. The negative sign encodes Lenz's Law: the induced current opposes the change that created it. For a coil of N turns: EMF = −NΔΦ/Δt. In the exam, always apply Lenz's law to determine current direction: ask "what change in flux is occurring?" then "what current direction would create a field opposing that change?"

AC generators and transformers: AC generator: rotating coil in a magnetic field produces sinusoidal EMF (E = E_max sinωt). Transformer: V_s/V_p = N_s/N_p and (assuming ideal) V_p I_p = V_s I_s. Transformers work only with AC because they rely on changing flux.

The Nature of Light (Module 7)

The photoelectric effect: Light below a threshold frequency (f₀) ejects no electrons regardless of intensity; above f₀, the maximum kinetic energy of ejected electrons depends on frequency, not intensity. Einstein's explanation: light is quantised in photons of energy E = hf. Maximum KE = hf − φ (work function). This experiment provided evidence against the classical wave model and supported the photon model.

Special relativity: Two postulates: (1) laws of physics are the same in all inertial reference frames; (2) the speed of light is constant in all inertial reference frames regardless of the motion of the source or observer.

Time dilation: t = γt₀ where t₀ is proper time (measured in the rest frame of the event), γ = 1/√(1−v²/c²). A moving clock runs slow (t > t₀).

Length contraction: L = L₀/γ where L₀ is proper length (measured in the rest frame of the object). A moving object is shortened in the direction of motion.

Mass-energy equivalence: E = mc². A mass defect Δm corresponds to energy ΔE = Δmc².

The conceptual challenge: these effects are not illusions or measurement errors — they are actual physical consequences of the constant speed of light.

From the Universe to the Atom (Module 8)

Nuclear physics: Binding energy = (mass of individual nucleons − mass of nucleus) × c². This mass defect represents the energy released when the nucleus formed. Nuclear fusion of light nuclei releases energy because the product has greater binding energy per nucleon than the reactants. Nuclear fission of heavy nuclei releases energy for the same reason (the products are near the peak of the binding energy per nucleon curve, around Fe-56).

Radioactive decay: Alpha decay (loses 2p, 2n — mass number decreases by 4, atomic number by 2), beta-minus decay (neutron → proton + electron + antineutrino), beta-plus/electron capture. Half-life: N = N₀(½)^(t/t½). Calculate the fraction remaining after n half-lives: (½)^n.

Standard Model: Quarks (up, down, strange, charm, top, bottom — know charges), leptons (electron, muon, tau, and their neutrinos), and bosons (force carriers: photon for EM, W and Z for weak nuclear, gluon for strong nuclear). Antimatter has opposite charge. Quarks combine in hadrons: baryons (3 quarks — proton = uud, neutron = udd), mesons (quark + antiquark).

Use the Spaced Repetition Flashcard Tool for formula derivations and definitions, and the Cornell Notes Tool for Working Scientifically analysis templates (error identification, reliability vs validity, improvement suggestions). See the HSC Chemistry study guide for parallel strategies on the other major HSC science.