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Introduction to Physics

15 free hands-on lessons in 5 modules, plus 21 more in 7 Pro modules. Start at the top — Module 0 builds every bit of math you'll need, from scratch.

Stuck on a step? Math for Physics teaches each piece of math the lessons use, and every lesson links to the parts it needs.

0

The Math Toolkit

Just enough math to read the language of physics — no prior skills needed.

Equations Are Balances

Every formula is a see-saw. Learn to keep it level.

12 min50 XPFree preview

Units & Powers of Ten

From atoms to galaxies with one slider.

10 min50 XPFree preview

Vectors: Arrows With Meaning

Some quantities need a direction, not just a size.

14 min60 XP

1

Motion

Describing how things move: position, velocity, acceleration.

Position & Velocity

Drive a car, watch the graph draw itself.

12 min60 XP

Acceleration

Not 'going fast' — changing how fast you go.

14 min70 XP

Free Fall

A hammer and a feather, on Earth and on the Moon.

14 min70 XP

Projectile Motion

Launch a cannonball. Find the perfect angle.

16 min80 XP

2

Forces & Newton's Laws

Why things move the way they do.

Inertia — Newton's First Law

Slide a puck on ice and watch it refuse to stop.

12 min70 XP

F = ma — Newton's Second Law

Push a crate. Feel the friction.

16 min90 XP

Action & Reaction — Newton's Third Law

Two skaters push off. Who wins?

12 min70 XP

3

Energy & Momentum

The two great bookkeeping rules of the universe.

Energy & Its Conservation

A skater on a ramp, and the bars that never change total.

16 min90 XP

Momentum & Collisions

Crash carts together. The total never lies.

15 min90 XP

4

Gravity, Oscillations & Waves

Planets, pendulums, and ripples — the same ideas, scaled up.

Gravity & Orbits

Throw a moon. Miss the planet. You're orbiting.

16 min100 XP

Springs & Oscillations

Pull, release, and watch the rhythm.

14 min90 XP

Waves

Shake a string and see energy travel without matter going anywhere.

14 min90 XP

5

Rotation Pro

Spinning, turning and balancing: Newton's laws go round in circles.

Circular Motion

Swing a ball on a string, then cut the string.

15 min100 XP

Torque & Balance

Balance a see-saw with a child and a grown-up.

15 min100 XP

Spinning & Angular Momentum

Pull your arms in and spin faster, like a figure skater.

16 min110 XP

6

Fluids Pro

Pressure, floating and flow: why ships float and planes fly.

Pressure & Depth

Dive deeper and feel the water squeeze.

14 min100 XP

Floating & Sinking

Drop blocks of wood, ice and steel into water, oil and honey.

15 min100 XP

Flow & Bernoulli

Squeeze a pipe and watch the water speed up.

15 min110 XP

7

Heat & Thermodynamics Pro

Temperature is jiggling atoms, and heat always flows downhill.

Temperature & Heat

Heat a box of gas and watch the atoms speed up.

15 min100 XP

Gases & Pressure

Squeeze a piston and heat the gas inside.

15 min100 XP

Heat Flow & Equilibrium

Drop a hot block into cold water and predict where it ends up.

16 min110 XP

8

Electricity Pro

Charges, currents and circuits: the physics inside every gadget.

Electric Charge & Force

Two charges: push them together, pull them apart.

15 min100 XP

Current, Voltage & Resistance

Turn up the battery and watch the bulb glow.

15 min100 XP

Series & Parallel Circuits

Wire two bulbs two ways and compare.

16 min110 XP

9

Magnetism & Induction Pro

Moving charges make magnetism, and moving magnets make electricity.

Magnets & Magnetic Forces

Fire a charged particle into a magnetic field and watch it curl.

16 min110 XP

Electromagnetic Induction

Spin a coil between two magnets and make your own electricity.

16 min110 XP

10

Light & Optics Pro

Bending, focusing and interfering: what light does, and what it is.

Reflection & Refraction

Shine a ray into glass and water, then trap it inside.

15 min100 XP

Lenses & Images

Slide a candle toward a lens and watch its image flip, grow and vanish.

16 min110 XP

Interference: Light as a Wave

Send light through two slits and get stripes instead of two lines.

16 min110 XP

11

Modern Physics Pro

Relativity, photons, nuclei and quarks: the physics of the last 120 years.

Special Relativity

Ride a light clock at 90% of light speed and watch time stretch.

18 min120 XP

Photons & Energy Levels

Shine light on a metal: colour matters, brightness doesn't.

17 min120 XP

Radioactivity & Nuclear Energy

Watch a thousand nuclei decay at random, and a perfect curve appear.

17 min120 XP

Particles & the Standard Model

Build a proton out of quarks.

16 min120 XP