81 interactive lessons · no math background needed

Physics you can touch.

Push crates, launch cannonballs, fling moons into orbit. Every idea comes with a live simulation, a plain-English explanation of why the world works that way, and the math — built step by step from your own numbers.

Start learning — it's free Try a lesson first

Start any lesson right now without an account, and dip into the exercises, past exams and library too.

Every lesson follows the way your brain actually learns

Intuition first, formula second, and never a symbol you haven't been introduced to.

1. Play

Start with a live simulation. Make predictions, break things, build a gut feeling.

2. Understand why

Plain-English explanations of the reason behind each law — not just what it says.

3. See the math

Every symbol explained. Formulas recomputed live with the numbers from your experiment.

4. Check yourself

Short quizzes with full explanations. Earn XP, keep a streak, track your progress.

Math-friendly by design

Scared of equations? Perfect.

Module 0 starts from “what does the = sign mean?”. After that, every formula comes with a card that explains each symbol, a sentence telling you how to read it out loud, and worked examples you reveal one step at a time.

Equations taught as balance scales
A colour code: velocity is always blue, force is always orange
Live 'math with your numbers' under every simulation
Glossary pop-ups for every new word

Want the math on its own, at your pace? Math for Physics is a companion course of 34 lessons, from fractions to first steps in calculus. Each physics lesson links to the math it uses.

Newton's second law

\textcolor{#f97316}{F} = \textcolor{#64748b}{m}\,\textcolor{#f59e0b}{a}

Say it out loud: “force equals mass times acceleration.”

FForce — the push or pull, in newtons

mMass — how hard it is to get moving, in kg

aAcceleration — change in velocity each second

The courses

Introduction to Physics

See the physics lessons

The Math Toolkit

· Equations Are Balances
· Units & Powers of Ten
· Vectors: Arrows With Meaning

Motion

· Position & Velocity
· Acceleration
· Free Fall
· Projectile Motion

Forces & Newton's Laws

· Inertia
· F = ma
· Friction, Slopes & Air Resistance
· Action & Reaction

Energy & Momentum

· Energy & Its Conservation
· Work, Power & Efficiency
· Momentum & Collisions

Gravity, Oscillations & Waves

· Gravity & Orbits
· Springs & Oscillations
· Waves
· Sound

RotationPro

· Circular Motion
· Torque & Balance
· Spinning & Angular Momentum

FluidsPro

· Pressure & Depth
· Floating & Sinking
· Flow & Bernoulli

Heat & ThermodynamicsPro

· Temperature & Heat
· Gases & Pressure
· Heat Flow & Equilibrium
· Melting, Boiling & Expansion
· Heat Engines & the Laws of Thermodynamics

ElectricityPro

· Electric Charge & Force
· Electric Field & Potential
· Capacitors & the RC Time Constant
· Current, Voltage & Resistance
· Series & Parallel Circuits
· Electric Power & the Electricity Bill

Magnetism & InductionPro

· Magnets & Magnetic Forces
· Electromagnetic Induction

Light & OpticsPro

· Electromagnetic Waves & the Spectrum
· Mirrors & Images
· Refraction & Total Internal Reflection
· Lenses & Images
· Interference: Light as a Wave

Modern PhysicsPro

· Special Relativity
· Photons & Energy Levels
· Matter Waves & the Uncertainty Principle
· Radioactivity & Nuclear Energy
· Particles & the Standard Model

Math for Physics

The companion course: every piece of math the physics uses, with the same diagrams, quizzes and practice.

See the math lessons

Numbers & Proportion

· Fractions, Ratios & Percentages
· Powers & Roots
· Direct, Inverse & Square Proportion
· Area, Volume & Density

Algebra & Graphs

· Rearranging Formulas
· Straight Lines & Slope
· Parabolas & Quadratics

Triangles, Circles & Waves

· Right Triangles & Pythagoras
· Sine, Cosine & Tangent
· Circles & Radians
· Sine Waves
· Trig Identities: Sums, Doubles & Beats

Growth & LogarithmsPro

· Functions & Inverses: Running Rules Backwards
· Sequences: Adding Steps and Multiplying Them
· Exponential Growth & Decay
· Logarithms

First Steps in CalculusPro

· Rates of Change: Derivatives
· Finding the Best: Optimization
· Adding Up Slices: Integrals
· Motion with Calculus: Slopes Down, Areas Up

Vectors & Simultaneous EquationsPro

· Simultaneous Equations
· Multiplying Vectors: Dot & Cross

Measurement & DataPro

· Measurement & Uncertainty
· Best-Fit Lines & Straightening Curves
· Dimensional Analysis: Let the Units Do the Work

Calculus in ActionPro

· Derivative Rules: Sines, Exponentials & Chains
· Differential Equations: Laws of Change
· Approximations: sin θ ≈ θ and Friends

Chance & StatisticsPro

· Probability: Counting the Chances
· Random Variables: Expected Value & Spread
· The Bell Curve & Standard Deviation
· Confidence Intervals: How Sure Is a Measurement?

Complex NumbersPro

· Complex Numbers: Numbers as Arrows
· Euler's Formula & Phasors

Practise on real problems. Then sit a real exam.

When a lesson clicks, make it stick. Everything here is free and needs no account.

Example 2.9 from College Physics

Calculating Final Velocity: An Airplane Slowing Down after Landing

An airplane lands with an initial velocity of 70.0 m/s and then decelerates at 1.50 m/s² for 40.0 s. What is its final velocity?

Strategy

Draw a sketch. We draw the acceleration vector in the direction opposite the velocity vector because the plane is decelerating.

Show the next step: solution

1 of 3 steps open

3,376 worked problems

Worked examples from 8 open textbooks: 486 in physics and 2,890 in math. Solve one on paper, open the solution a step at a time, then mark it solved or save it to review.

Browse the exercises

2025, Paper 1 90:0020 multiple choice + 5 written · 51 marks

36 official exam papers

Queensland's final-year QCE exams in Physics, Mathematical Methods and Specialist Mathematics, 2020–2025, exactly as students sat them: 673 questions. Time yourself, get the multiple choice marked, then check your written answers against the official marking guide.

Sit a past exam

9 free textbooks

Complete OpenStax books for physics and math to read right here, plus a reading list of the 23 books we'd hand a student who wants more.

Visit the library

Built on sources you can trust

Explanations follow open, peer-reviewed textbooks and world-class references — every lesson lists its sources so you can dig deeper. The exercises and the library are OpenStax's own books, and the past exams are the official QCAA papers.

OpenStax (physics and math) Active Calculus The Feynman Lectures (Caltech) HyperPhysics (Georgia State) NASA NIST & BIPM PhET (CU Boulder) QCAA (Queensland)

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