Playground
Simulations
Every simulation from both courses, free to play with. Set one up the way you like, then press Share to copy a link to exactly that setup.
Introduction to Physics
The Math ToolkitThe equation balanceSolve equations by keeping a see-saw level.Open The Math ToolkitZoom through the universeFrom atomic nuclei to galaxy clusters with one slider.Open The Math ToolkitVector playgroundDrag two arrows and add them tip to tail.Open MotionDrive the carSet a speed and watch the position graph draw itself.Open MotionAccelerating carChange the acceleration and see the graph curve.Open MotionArea under the velocity graphWhy distance is the area under a velocity–time graph.Open MotionHammer and feather dropDrop them in air, in a vacuum and on the Moon.Open MotionProjectile motion simulatorLaunch a cannonball: pick the angle, speed and planet, then hit the target.Open Forces & Newton's LawsSlide the puckKick a puck across carpet, wood, ice and a frictionless surface.Open Forces & Newton's LawsPush the crate (F = ma)Push against friction and see the free-body diagram.Open Forces & Newton's LawsTwo skaters push offNewton's third law with skaters of different masses.Open Energy & MomentumEnergy skate parkWatch kinetic and potential energy trade places on a ramp.Open Energy & MomentumCollision labCrash two carts: elastic, partly elastic or sticky.Open Gravity, Oscillations & WavesWhy gravity is 1/r²See a force spread out over a growing sphere.Open Gravity, Oscillations & WavesNewton's cannon (orbit simulator)Fire a cannonball fast enough and it never lands.Open Gravity, Oscillations & WavesSpring and pendulum labMeasure periods of springs and pendulums.Open Gravity, Oscillations & WavesWave on a stringShake a string: frequency, wavelength, speed and reflections.Open RotationBall on a string (circular motion)Whirl a ball, then cut the string and see which way it flies.Open RotationSee-saw balance (torque)Balance two people by moving them along a see-saw.Open RotationSpinning skater (angular momentum)Pull the arms in and the spin speeds up.Open FluidsPressure under waterLower a probe into water, oil or honey and read the pressure.Open FluidsFloat or sink? (buoyancy)Drop cork, wood, ice, brick or steel into different liquids.Open FluidsWater in a narrowing pipe (Bernoulli)Squeeze a pipe: faster flow, lower pressure.Open Heat & ThermodynamicsMolecules in a box (temperature)Heat a gas and watch its molecules speed up.Open Heat & ThermodynamicsGas under a piston (PV = nRT)Squeeze and heat a gas, read the pressure.Open Heat & ThermodynamicsHeat flow between two blocksTouch a hot block to a cold one and predict the final temperature.Open ElectricityCoulomb's law (electric force)Two charges: attract, repel, and the inverse-square law.Open ElectricityOhm's law circuitTurn up the battery or the resistance and watch the bulb.Open ElectricitySeries vs parallel circuitsWire two bulbs both ways, then remove one.Open Magnetism & InductionA charge in a magnetic fieldFire a proton into a field and watch it turn a half circle.Open Magnetism & InductionAC generator (Faraday's law)Spin a coil between two magnets and graph the flux and the voltage.Open Light & OpticsReflection and refraction (Snell's law)Shine a ray between air, water, glass and diamond, and find total internal reflection.Open Light & OpticsLens ray diagramSlide an object toward a lens and watch the image flip, grow and turn virtual.Open Light & OpticsYoung's double slitChange the colour and the slits, and watch the interference fringes move.Open Modern PhysicsLight clocks (time dilation)Fly a light clock at nearly light speed and watch it fall behind.Open Modern PhysicsThe photoelectric effectShine light of any colour on four metals and catch the electrons.Open Modern PhysicsRadioactive decay and half-lifeWatch 400 nuclei decay at random, and a perfect curve emerge.Open Modern PhysicsBuild a particle from quarksCombine up, down and strange quarks into protons, neutrons and pions.Open
Math for Physics
Numbers & ProportionMix the paint (ratios)Scale a paint recipe and watch the colour stay the same.Open Numbers & ProportionThe square–cube lawScale a square and a cube: area ×k², volume ×k³.Open Numbers & ProportionDirect, inverse and square proportionMultiply x by k and see what happens to y under four laws.Open Algebra & GraphsSolve a formula for any letterRearrange F = ma, v = u + at, E = ½mv² and P = F/A step by step.Open Algebra & GraphsStraight lines and slopeTilt y = mx + b and read the slope as a rate, or as a velocity.Open Algebra & GraphsParabolas and a thrown ballShape y = ax² + bx + c, find its roots, then throw a ball.Open Triangles, Circles & WavesPythagoras with real squaresBuild a square on each side of a right triangle and compare the areas.Open Triangles, Circles & WavesSine, cosine and tangentChange the angle of a right triangle, then go round the unit circle.Open Triangles, Circles & WavesWhat is a radian?Lay radius-lengths around a circle and count them.Open Triangles, Circles & WavesA circle draws a sine waveSpin a point round a circle and record its height: amplitude, frequency, phase.Open Growth & LogarithmsExponential growth and decayDoubling times and half-lives, against a straight line.Open Growth & LogarithmsThe log ruler and decibelsSlide a number from 1 to a trillion on an ordinary ruler and a log one.Open First Steps in CalculusSecant to tangent: the derivativeShrink the gap between two points and zoom in until the curve is straight.Open First Steps in CalculusRiemann sums: the integralFill the area under a curve with thinner and thinner bars.Open Vectors & Simultaneous EquationsTwo equations, one crossingMove two lines and find where they meet, or stage a car chase.Open Vectors & Simultaneous EquationsDot and cross productsTurn one arrow and watch its shadow and the parallelogram change.Open Measurement & DataRepeated measurementsTime a pendulum again and again, and find the mean and the uncertainty.Open Measurement & DataStraighten the curve, read off gPlot pendulum data as T² against L and fit a line to measure g.Open