Simulations Interactive simulations by topic
Free simulations you can run in a browser to explore each topic: change the variables, predict what will happen, then check. Most run on phones and tablets too. All resources
Simulations marked computer only are older PhET simulations: they run in a browser on a computer, but not on most phones.
General
- PhET Interactive Simulations ↗ University of Colorado BoulderResearch-based simulations for almost every topic.
- oPhysics ↗ Tom WalshHundreds of short simulations, sorted by area of physics.
- Physics apps by Walter Fendt ↗ Walter FendtSimple, clear simulations of classic experiments.
- Physics Interactives ↗ The Physics ClassroomSimulations with short tasks to work through.
- The Physics Aviary ↗ Frank LeeVirtual labs and practice problems: take measurements from a simulation and analyse them.
- myPhysicsLab ↗ Erik NeumannSimulations of springs, pendulums, collisions and rolling, with the equations behind them.
- Physion ↗ PhysionDraw your own 2D physics simulations with shapes, springs and joints. Editing needs a computer.
- Vector Addition ↗ PhETAdd and resolve vectors (see Skills: vectors).
Theme A: Space, time and motion
A.1 Kinematics Notes →
- Projectile Motion ↗ PhETChange the launch angle, speed and air resistance, and watch the trajectory.
- Motion with Constant Acceleration ↗ Walter FendtDisplacement, velocity and acceleration graphs drawn as an object moves.
- Projectile Motion ↗ Walter FendtVelocity components shown at every point of the path.
- Kinematics simulations ↗ oPhysicsMotion graphs, relative velocity, projectiles and more.
A.2 Forces and momentum Notes →
- Forces and Motion: Basics ↗ PhETBalanced and unbalanced forces, friction and acceleration.
- Friction ↗ PhETWhat happens between two surfaces when they rub together.
- Collision Lab ↗ PhETElastic and inelastic collisions in one and two dimensions, with momentum vectors.
- Elastic and Inelastic Collision ↗ Walter FendtMomentum and kinetic energy before and after a collision.
- Uniform Circular Motion ↗ Walter FendtVelocity and centripetal acceleration vectors around a circle.
- Forces simulations ↗ oPhysicsFree-body diagrams, inclined planes, friction and more.
A.3 Work, energy and power Notes →
- Energy Skate Park ↗ PhETKinetic, potential and thermal energy as a skater moves, with friction on or off.
- Hooke's Law ↗ PhETForce, extension and elastic potential energy of springs.
- Conservation simulations ↗ oPhysicsEnergy and momentum conservation, including the ballistic pendulum.
A.4 Rigid body mechanics Notes →
- Balancing Act ↗ PhETBalance torques on a see-saw.
- Torque ↗ PhET computer onlyTorque, moment of inertia and angular acceleration.
- Lever Principle ↗ Walter FendtMoments about a pivot.
- Rotation simulations ↗ oPhysicsRolling motion, moment of inertia and angular momentum.
A.5 Galilean and special relativity Notes →
- Time Dilation ↗ Walter FendtA moving clock compared with clocks at rest.
Theme B: The particulate nature of matter
B.1 Thermal energy transfers Notes →
- States of Matter ↗ PhETParticles in solids, liquids and gases, and changes of state.
- Energy Forms and Changes ↗ PhETHeating, thermal energy transfer and thermal equilibrium.
- Blackbody Spectrum ↗ PhETHow the spectrum of a hot object changes with temperature (Wien's law).
B.2 Greenhouse effect Notes →
- Greenhouse Effect ↗ PhETSunlight, infrared and the energy balance of the Earth.
- Molecules and Light ↗ PhETWhich molecules absorb infrared, and what happens when they do.
B.3 Gas laws Notes →
- Gas Properties ↗ PhETPressure, volume, temperature and the speeds of the particles.
- Gases Intro ↗ PhETExplore Boyle's law and Charles's law.
B.4 Thermodynamics Notes →
- Special Processes of an Ideal Gas ↗ Walter FendtIsobaric, isochoric, isothermal and adiabatic changes on a p–V diagram.
- Carnot Cycle ↗ Walter FendtThe four stages of a Carnot engine.
B.5 Current and circuits Notes →
- Circuit Construction Kit: DC ↗ PhETBuild circuits and measure current and potential difference.
- Resistance in a Wire ↗ PhETHow resistivity, length and area affect resistance.
- Ohm's Law ↗ PhETHow V, I and R are related.
- Circuit Simulator ↗ FalstadA powerful circuit simulator, with current shown moving.
- Combinations of Resistors ↗ Walter FendtResistors in series and parallel.
- Potentiometer ↗ Walter FendtA potential divider in action.
Theme C: Wave behaviour
C.1 Simple harmonic motion Notes →
- Pendulum Lab ↗ PhETPeriod, length, mass and energy of a pendulum.
- Masses and Springs ↗ PhETOscillating springs, with energy bars.
- Simple Pendulum ↗ Walter FendtDisplacement, velocity and acceleration graphs of SHM.
- Spring Pendulum ↗ Walter FendtA mass–spring oscillator with graphs.
C.2 Wave model Notes →
- Waves Intro ↗ PhETWater, sound and light waves.
- Wave on a String ↗ PhETAmplitude, frequency, wavelength and wave speed.
- Sound Waves ↗ PhET computer onlySound as a longitudinal wave.
- Electromagnetic Wave ↗ Walter FendtElectric and magnetic fields in an electromagnetic wave.
- Waves simulations ↗ oPhysicsTransverse and longitudinal waves, superposition and more.
C.3 Wave phenomena Notes →
- Wave Interference ↗ PhETTwo-source and double-slit interference with water, sound and light.
- Bending Light ↗ PhETRefraction, Snell's law and total internal reflection.
- Ripple Tank ↗ FalstadDiffraction and interference of water waves.
- Interference of Light at a Double Slit ↗ Walter FendtPath difference and the double-slit pattern.
- Diffraction of Light by a Single Slit ↗ Walter FendtThe single-slit intensity pattern.
- Light simulations ↗ oPhysicsRefraction, interference, diffraction gratings and more.
C.4 Standing waves and resonance Notes →
- Standing Wave ↗ Walter FendtA standing wave formed by a wave and its reflection.
- Standing Longitudinal Waves ↗ Walter FendtStanding waves in pipes, open and closed.
- Forced Oscillations (Resonance) ↗ Walter FendtAmplitude against driving frequency, with damping.
- Loaded String ↗ FalstadHarmonics on a string.
C.5 Doppler effect Notes →
- Doppler Effect ↗ Walter FendtWavefronts from a moving source and a moving observer.
Theme D: Fields
D.1 Gravitational fields Notes →
- Gravity and Orbits ↗ PhETThe Sun, Earth, Moon and a satellite, with force and velocity vectors.
- Gravity Force Lab ↗ PhETNewton's law of gravitation.
- Kepler's Laws ↗ PhETElliptical orbits, equal areas and the third law.
- My Solar System ↗ PhETDesign your own system of orbiting bodies.
D.2 Electric and magnetic fields Notes →
- Coulomb's Law ↗ PhETThe force between two charges.
- Charges and Fields ↗ PhETElectric field lines and equipotentials around charges.
- Magnetic Field of a Bar Magnet ↗ Walter FendtField lines around a bar magnet.
- Magnetic Field of a Straight Current-Carrying Wire ↗ Walter FendtField lines around a wire.
- E & M simulations ↗ oPhysicsFields, forces on charges and more.
D.3 Motion in electromagnetic fields Notes →
- Lorentz Force ↗ Walter FendtThe force on a current-carrying wire in a magnetic field.
- Direct Current Electrical Motor ↗ Walter FendtHow the motor effect makes a motor turn.
D.4 Induction Notes →
- Faraday's Law ↗ PhETMove a magnet through a coil and watch the induced emf.
- Faraday's Electromagnetic Lab ↗ PhETCoils, electromagnets, transformers and generators.
- Generator ↗ PhETA water wheel turns a magnet to generate electricity.
- Generator ↗ Walter FendtAn ac generator and its output.
Theme E: Nuclear and quantum physics
E.1 Structure of the atom Notes →
- Rutherford Scattering ↗ PhETAlpha particles fired at gold atoms.
- Models of the Hydrogen Atom ↗ PhETCompare models of the atom with experiment.
- Build an Atom ↗ PhETProtons, neutrons, electrons, isotopes and ions.
- Bohr's Theory of the Hydrogen Atom ↗ Walter FendtEnergy levels and orbits in the Bohr model.
E.2 Quantum physics Notes →
- Photoelectric Effect ↗ PhET computer onlyChange the wavelength and intensity and watch the electrons.
- Photoelectric Effect ↗ Walter FendtStopping potential against frequency.
- Davisson–Germer: Electron Diffraction ↗ PhET computer onlyElectrons diffracting off a crystal.
- Quantum Wave Interference ↗ PhETPhotons and electrons through a double slit.
E.3 Radioactive decay Notes →
- Isotopes and Atomic Mass ↗ PhETStable and unstable isotopes.
- Alpha Decay ↗ PhET computer onlyAlpha decay and half-life.
- Beta Decay ↗ PhET computer onlyBeta decay and half-life.
- Law of Radioactive Decay ↗ Walter FendtRandom decay of many nuclei, and the decay curve.
- Radioactive Decay Chains ↗ Walter FendtHow heavy nuclei decay step by step.
E.4 Fission Notes →
- Nuclear Fission ↗ PhET computer onlyFission, chain reactions and a model reactor.
E.5 Fusion and stars Notes →
- Blackbody Spectrum ↗ PhETCompare the spectra of stars of different temperatures.
- Stellarium Web ↗ StellariumA planetarium in your browser: find stars and see their colours.