About USAPhO
The AAPT's invitational physics olympiad, a calculus-based free-response exam for students who score highly on the F=ma exam.
USAPhO Exam Format & Focus
A 3-hour free-response exam in two parts: Part A (90 minutes, 3 multi-part problems) and Part B (90 minutes, 3 multi-part problems). Topics are mechanics, electricity and magnetism, thermodynamics, waves and optics, and modern physics and relativity.
How Skillzy Young Scholars Prepares Students for USAPhO
Skillzy Young Scholars teaches USAPhO in live online classes with vetted mentors who have completed 100 hours of training. The curriculum is organised into 8 units, with worksheets, quizzes, timed practice and mock exams. Progress is tracked in the LMS and shared with parents in a monthly report.
What USAPhO Covers
- Advanced mechanics: non-inertial frames and rigid-body dynamics
- Electricity and magnetism, including circuits and induction
- Thermodynamics, waves and optics
- Special relativity and quantum phenomena
USAPhO Curriculum
Classes follow these units. Every student starts with a level check, and the order and pace adapt to your child. Units that go beyond the exam's core topics are stretch material.
- Target Audience
- High school students in Grades 9–12 who qualify based on top scores on the nationwide F = ma Exam (~top 400 students).
- Exam Structure & Format
- 3-hour, free-response examination split into two parts:
- 1. Part A: 90 minutes for 3 multi-part free-response problems.
- 2. Part B: 90 minutes for 3 multi-part free-response problems.
- Core Subject Coverage
- Mechanics (~30%), Electricity & Magnetism (~30%), Thermodynamics (~15%), Waves & Optics (~15%), Modern Physics & Relativity (~10%).
- Scoring & Awards
- Full partial credit awarded for logical physical steps, clear derivations, and proper vector notation. Top scorers earn Gold, Silver, Bronze, or Honorable Mention Medals, with the top 20 students overall invited to the 10-day US Physics Team Training Camp to compete for the 5-member International Physics Olympiad (IPhO) team.
What the program focuses on
- Advanced Mechanics & Non-Inertial Systems (Lagrangian-style reasoning, pseudo-forces, Coriolis/centrifugal effects, and 3D rigid-body rotation)
- Electricity & Magnetism (Gauss's Law, Ampere's Law, Faraday's Law of Induction, Maxwell's equations, and RC/RL/RLC circuits)
- Thermodynamics & Statistical Kinetic Theory (PV/TS diagrams, heat engine efficiency, Carnot cycles, entropy, and Maxwell-Boltzmann distributions)
- Waves & Physical Optics (wave equations, interference, single/double slit diffraction, thin-film optics, and polarization)
- Modern Physics & Relativity (special relativity Lorentz transformations, relativistic momentum/energy, photoelectric effect, and Bohr/quantum models)
- Interactive, hands-on free-response derivation labs and mock Olympiad exams with continuous progress monitoring
Units
1 Non-Inertial Reference Frames & Pseudo-Forces
Students will learn to:
- Analyze Accelerating Reference Frames: Formulate equations of motion in linearly accelerating → → frames by introducing fictitious/pseudo-forces (Fpseudo =− maframe). → → → →
- Master Rotating Reference Frames: Derive centrifugal force (Fcentrifugal =− mω × (ω × r)) and → → → Coriolis force (Fcoriolis =− 2m(ω × vrot)).
- Analyze Foucault Pendulums & Global Motions: Calculate precessional rates of Foucault pendulums and deflection of projectiles due to Earth's rotation at arbitrary latitudes φ.
- Apply Equivalence Principle Intuition: Utilize Einstein's principle of equivalence to analyze gravitational red-shift and accelerated frame light bending conceptually.
USAPhO Alignment - Advanced Mechanics. USAPhO free-response mechanics questions frequently require frame transformations to non-inertial systems to simplify complex multi-body orbits or fluid surface profiles.
Learning activities:
- Coriolis deflection and centrifugal force derivation workshops 2 2 ωr
- Rotating fluid surface profile (y = 2g ) integration labs
- Foucault pendulum precessional frequency calculation problem sets
What this means for your child. Your child will master non-inertial mechanics, calculating Coriolis forces, centrifugal acceleration, and frame transformations.
2 3D Rigid-Body Dynamics & Virtual Work
Students will learn to:
- Master Moment of Inertia Tensors: Calculate moments of inertia for continuous 2D/3D bodies using integration and the Parallel/Perpendicular Axis Theorems. → → →
- Analyze 3D Rigid-Body Rotations: Formulate angular momentum vector equations (L = Iω) where L → → → → and ω are non-collinear; analyze gyroscopic precession (τ = Ωp × L).
- Apply Energy & Virtual Work Methods: Solve complex equilibrium and constrained mechanical systems using the Principle of Virtual Work (∑ δWi = 0) and generalized coordinates.
- Apply Informal Lagrangian Reasoning: Set up kinetic and potential energy expressions (L = T − U) to find equations of motion without drawing complex force vectors.
USAPhO Alignment - Advanced Mechanics. Rigid-body rotation involving non-symmetric inertia tensors, gyroscopic precession, and virtual work equilibrium are signature USAPhO free-response topics.
Learning activities:
- 3D gyroscopic precession rate (Ωp = Iω ) derivation labs
- Continuous body moment of inertia integration speed relays
- Principle of Virtual Work mechanical equilibrium workshops
What this means for your child. Your child will learn advanced 3D rigid-body dynamics, deriving moment of inertia integration and gyroscopic precession.
3 Vector Field Calculus, Gauss's Law, & Electric Potential
Students will learn to:
- Apply Vector Calculus in E&M: Use gradient (∇V), divergence (∇ · E), and curl (∇ × E) operators in Cartesian, cylindrical, and spherical coordinates. → → Qenc
- Master Gauss's Law (Integral & Differential): Apply ΦE = ∮ E · dA = ε0 to continuous charge distributions (spheres, infinite cylinders, planar sheets).
- Calculate Electric Potential & Field Integrals: Compute V(r) = -∫_∞r E · dl and calculate electrostatic potential energy of continuous charge distributions.
- Solve Conductors, Capacitors, & Dielectrics: Analyze conductor surface charge distributions, image charge methods, multi-plate capacitors, and dielectric polarization (κ, ε).
USAPhO Alignment - Electricity & Magnetism. USAPhO E&M problems demand rigorous vector field integration over continuous geometries and image-charge calculations.
Learning activities:
- Gauss's Law non-uniform charge density integration workshops
- Method of Image Charges for grounded conducting planes labs
- Dielectric insertion electrostatic energy change derivation problem sets
What this means for your child. Your child will master advanced electrostatics, applying Gauss's Law integrations and continuous electric potential field equations.
4 Ampere's Law, Induction, & RC/RL/RLC Circuits
Students will learn to:
- Apply Biot-Savart & Ampere's Laws: Compute magnetic fields B for complex current configurations dΦB
- Master Faraday's Law & Maxwell's Equations: Calculate induced electromotive force (E =− dt ), Lenz's Law directions, self/mutual inductance (L, M), and displacement current.
- Analyze Transients in RC & RL Circuits: Derive first-order differential equations governing charging/discharging capacitors and inductors (q(t), i(t)) using calculus.
- Analyze AC Oscillations in RLC Circuits: Formulate second-order differential equations for harmonic RLC oscillations, calculating resonant frequency (ω0 = ), quality factor (Q), and impedance (Z). LC
USAPhO Alignment - Magnetism & Circuits. Calculus-based RLC differential equations and motional EMF induction problems account for significant points on USAPhO exams.
Learning activities:
- Biot-Savart Law line-integral magnetic field derivation labs
- Faraday's Law motional EMF and eddy-current damping workshops
- Second-order RLC differential equation circuit solving drills
What this means for your child. Your child will learn electromagnetism and circuits, deriving Biot-Savart integrations, induction laws, and second-order RLC circuit equations.
5 Thermodynamics, Kinetic Theory, & Heat Engines
Students will learn to:
- Master Laws of Thermodynamics: Apply First Law (∆U = Q − W) and Second Law (∆S ≥ 0) to γ isobaric, isochoric, isothermal, and adiabatic (PV = const) processes.
- Analyze Thermodynamic Diagrams (PV & TS): Calculate work (W = ∫ PdV), heat transfer, and Wnet efficiency (η = Qin ) for Carnot, Otto, Diesel, and Stirling cycles. 1 2
- Apply Kinetic Theory & Maxwell-Boltzmann: Derive gas pressure P = 3 nmvrms, internal energy f U = 2 nRT, equipartition theorem, and root-mean-square/most probable speeds. dQrev
- Calculate Entropy & Statistical State Counts: Calculate thermodynamic entropy changes ∆S = ∫ T and connect to Boltzmann's microstate equation (S = kB ln Ω).
USAPhO Alignment - Thermodynamics. USAPhO thermodynamics problems require deriving heat engine efficiencies on non-standard PV/TS cycles and calculating entropy changes.
Learning activities:
- Non-standard PV thermodynamic cycle efficiency derivation workshops
- Adiabatic gas expansion entropy change integration labs
- Maxwell-Boltzmann speed distribution derivation problem sets
What this means for your child. Your child will master thermodynamics and kinetic theory, deriving engine cycle efficiencies and statistical entropy changes.
6 Wave Equations, Interference, & Physical Optics
Students will learn to:
- Derive Classical Wave Equations: Solve 1D wave equations ( 2 = 2 2 ), standing wave boundary ∂x v ∂t conditions, and wave intensity (I ∝ A ).
- Analyze Physical Optics Interference: Derive Young's double-slit interference, thin-film phase shifts ( 2nt = mλ), and N-slit grating intensity distributions using complex phasors.
- Analyze Diffraction & Resolution: Compute single-slit Fraunhofer diffraction intensity profiles ( sinβ 2 I(θ) = I0 ( ) ) and Rayleigh's criterion for angular resolution (θ β min λ = 1. 22 D ).
- Master Geometric & Matrix Optics: Analyze thin/thick lens combinations, spherical mirrors, dispersion, and 2 × 2 ray transfer matrices (ABCD matrices).
USAPhO Alignment - Waves & Optics. Physical optics questions test complex phasor interference derivations, thin-film phase shifts, and Fraunhofer diffraction profiles.
Learning activities:
- Complex phasor N-slit interference derivation labs
- Fraunhofer single-slit diffraction intensity profile workshops
- Thin-film optical coating phase-shift calculation drills
What this means for your child. Your child will learn wave mechanics and physical optics, deriving phasor interference and Fraunhofer diffraction intensity profiles.
7 Special Relativity & Relativistic Dynamics
Students will learn to:
- Apply Postulates of Special Relativity: Understand constancy of light speed (c) and principle of relativity in all inertial frames.
- Master Lorentz Transformations: Derive and execute Lorentz space-time transformations (x', t'), length contraction (L = L0/γ), time dilation (∆t = γ∆t0), and relativistic velocity additions.
- Analyze Relativistic Momentum & Energy: Derive p = γmv, total energy E = γmc , kinetic energy 2 2 2 2 2 4 K = (γ − 1)mc , and mass-energy invariant (E − p c = m c ).
- Utilize Spacetime Diagrams & Invariants: Construct Minkowski space-time diagrams, worldlines, 2 2 2 light cones, and derive invariant spacetime intervals (s = (c∆t) − ∆x ).
USAPhO Alignment - Modern Physics. Relativity problems on USAPhO demand relativistic energy-momentum invariant calculations and space-time frame transformations.
Learning activities:
- Relativistic energy-momentum invariant E − p c = m c derivation labs
- Minkowski space-time diagram worldline plotting workshops
- Lorentz velocity addition and twin-paradox resolution problem sets
What this means for your child. Your child will master special relativity, calculating Lorentz transformations, spacetime invariants, and relativistic dynamics.
8 Quantum Phenomena, Photoelectric Effect, & Atomic Models
Students will learn to:
- Analyze Photoelectric & Compton Effects: Calculate photon momentum (p = h/λ), photoelectric work function thresholds (Kmax = hf − Φ), and Compton scattering wavelength shifts ( h ∆λ = m c (1 − cos θ)). e
- Understand De Broglie Wavelength & Wave-Particle Duality: Calculate matter wavelengths (λ = h/p) and analyze electron diffraction experiments.
- Analyze Bohr Atom & Hydrogen Spectroscopy: Derive Bohr radius (rn = n a0), energy levels ( 13.6eV En =− 2 ), and Rydberg formula spectral transitions. n
- Introduce 1D Quantum Mechanics: Analyze 1D particle-in-a-box energy quantization ( 2 nπx ħ ψn(x) = L sin L ) and Heisenberg uncertainty relations (∆x∆p ≥ 2 ).
USAPhO Alignment - Quantum Physics. Questions test Compton scattering energy conservation, Bohr model derivations, and 1D infinite square well energy states.
Always check the official exam organizer for the current format, dates and eligibility. We do not guarantee scores or rankings.
Sample USAPhO Prep Plan
- Begin with a USAPhO diagnostic and check the current official format, scoring rules and eligible level.
- Weeks 3–5: build a topic notebook, practise interpreting evidence and explain answers aloud.
- Weeks 6–8: complete timed sets and review weak concepts.
- Final phase: rehearse pacing, review past-style problems and refine written solutions.
Common USAPhO Mistakes We Help Students Avoid
- Preparing for USAPhO using a generic or outdated format instead of checking the current official guidance.
- Ignoring the official rules, scoring rubric or allowed materials.
- Leaving timed practice until the final week.
Every student begins with a level check so we can see where the gaps are. Private 1:1 students also get a full diagnostic assessment and a personalized roadmap. We teach the concepts behind each question type, practice under timed conditions, and review every wrong answer. We cannot guarantee specific scores, but progress is tracked in monthly reports.