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ScienceQuest

Simulators

Run a projectile, a pendulum, an RLC circuit or an action potential, change the numbers, and watch what the model does. Free, no sign-in.

56 tools across 7 subjects

Mechanics

Simulator · Mechanics Projectile Motion Simulator Animate a trajectory and read off range, apex and flight time as you change launch speed and angle. Simulator · Mechanics Elastic and Inelastic Collision Simulator Collide two bodies and watch momentum survive every time while kinetic energy only survives a perfect bounce. Simulator · Mechanics Simple Pendulum Simulator Swing a pendulum, add damping, and watch the small-angle approximation fail at large amplitude. Simulator · Mechanics Orbit Simulator One launch speed slider walks an orbit from circle through ellipse to escape. Simulator · Mechanics Mass Spring Simulator Simple harmonic motion with damping and a driving force, plus the resonance curve. Simulator · Mechanics Inclined Plane Simulator Tilt a slope, set the friction and a push, and see whether the block slides, how fast, and where its energy goes. Simulator · Mechanics Conservation of Energy Simulator A cart on a track you reshape, with kinetic, potential and thermal energy bars whose total never changes. Simulator · Mechanics Double Pendulum Simulator Two linked arms, a ghost released a millionth of a degree away, and the moment the two part company. Simulator · Mechanics Buoyancy Simulator Lower a block into a liquid on a spring balance and watch the buoyant force share its weight. Simulator · Mechanics Motion Graphs Simulator Run a cart through up to five stages and watch its x-t, v-t and a-t graphs draw, with live gradients and areas. Simulator · Mechanics PID Controller Simulator Tune Kp, Ki and Kd on a cart or an oven, with actuator limits, anti-windup and a sampled controller.

Chemistry

Simulator · Chemistry Collision Theory and Activation Energy Simulator See how few molecules clear the activation barrier, and why heating changes that so violently. Simulator · Chemistry Radioactive Decay Simulator Individual nuclei decaying at random, against the curve the formula predicts. Simulator · Chemistry Titration Lab Simulator A burette, an indicator and an exact pH meter, with your endpoint measured against equivalence. Simulator · Chemistry Rutherford Scattering Simulator Alphas fired at a nucleus: their exact paths, angles and closest approach, and the counts against Rutherford’s formula. Simulator · Chemistry Galvanic Cell Simulator Two metals, two solutions and a salt bridge, run down while the voltage falls and the electrodes change mass. Simulator · Chemistry Bohr Model and Hydrogen Spectrum Simulator Jump an electron between Bohr orbits and read the photon’s energy, wavelength and series. Simulator · Chemistry HPLC and GC Chromatography Simulator Watch two to four analytes separate on an HPLC or GC column, with retention times, plate count and resolution.

Biology

Simulator · Biology Action Potential Simulator Hodgkin-Huxley, with threshold and refractoriness emerging. Simulator · Biology Oxygen Dissociation Curve Simulator The sigmoid curve, and what moves it left or right. Simulator · Biology Enzyme Kinetics Simulator Km and Vmax, and how each inhibitor changes them. Simulator · Biology Nephron Explorer The loop, the gradient it builds, and what ADH can do with it. Simulator · Biology Resting Membrane Potential Simulator Nernst per ion, Goldman for the membrane. Simulator · Biology SIR Epidemic Model Simulator SIR and SEIR epidemics with R₀, herd immunity and vaccination. Simulator · Biology Predator-Prey Simulator Lotka-Volterra cycles over time and in the phase plane, with the equilibrium and exact period. Simulator · Biology Photosynthesis Rate Simulator Light, CO₂ and temperature against the rate, with the limiting factor named and pondweed bubbles counted. Simulator · Biology Cardiac Cycle Simulator Pressures, volume, valves and ECG through one heartbeat. Simulator · Biology Diffusion and Osmosis Simulator Diffusion or osmosis across one membrane, counted against Fick’s law. Simulator · Biology Mitosis and Meiosis Explorer Mitosis and meiosis stage by stage, with chromosome and chromatid counts for your 2n. Simulator · Biology Protein Synthesis Simulator Type a gene and watch RNA polymerase, a ribosome and tRNAs build its protein, step by step. Simulator · Biology qPCR and ΔΔCt Simulator Four Ct values to a fold change by 2^−ΔΔCt or Pfaffl, with amplification curves, a threshold and a standard curve. Simulator · Biology Muscle Twitch and Tetanus Simulator Fire a muscle at any frequency and watch single twitches sum into unfused and then fused tetanus. Simulator · Biology Pharmacokinetics Dosing Simulator Build repeated doses up to steady state and read the peak, trough, average, accumulation factor and loading dose. Simulator · Biology ECG Rhythm and Heart Block Simulator A sweeping lead II strip and ladder diagram for sinus rhythm, heart blocks, AF, flutter and ectopic beats. Simulator · Biology Gel Electrophoresis Simulator Run a virtual agarose gel with a ladder and digests, and size an unknown band from the semi-log standard curve. Simulator · Biology Spirometry and Flow-Volume Loop Simulator Watch normal, obstructive, restrictive and upper airway flow-volume loops form, with FEV1/FVC read out.

Electricity

Simulator · Electricity RC Charge and Discharge Simulator Charge a capacitor through a resistor and watch where the time constant comes from. Simulator · Electricity RLC Circuit Simulator A series RLC transient, from ringing through critical damping to sluggish. Simulator · Electricity Solenoid Magnetic Field Simulator The field through and around a real coil, and the halving at its ends. Simulator · Electricity Electric Field Simulator Point charges you can drag, with field lines, equipotentials and a probe reading E and V. Simulator · Electricity Electromagnetic Induction Simulator A magnet moved through a coil: induced EMF, current and Lenz’s law direction. Simulator · Electricity Series and Parallel Circuit Simulator Bulbs, switches and meters in series, parallel and bridge circuits, solved exactly. Simulator · Electricity Charged Particle in a Magnetic Field Simulator Circles, helices, a velocity selector and a mass spectrometer, from the exact Lorentz force. Simulator · Electricity Oscilloscope Simulator Two signal generators on a scope screen: set the volts/div, time/div and trigger, then read the trace off the grid.

Waves & Optics

Simulator · Waves & Optics Standing Wave Simulator Harmonics on a string, with the two travelling waves that superpose to make them. Simulator · Waves & Optics Ray Diagram Simulator The three principal rays, with the image located where they cross. Simulator · Waves & Optics Double Slit Simulator Interference fringes, and the single-slit envelope shaping them. Simulator · Waves & Optics Doppler Effect Simulator Wavefronts from a moving source, and the shift they produce. Simulator · Waves & Optics Wave Interference Simulator Two coherent sources, their nodal lines, and the path difference at any point. Simulator · Waves & Optics Refraction Simulator Rays through a boundary, a glass block and a prism, with total internal reflection and white light split into colours. Simulator · Waves & Optics Photoelectric Effect Simulator Which light frees electrons from a metal, how fast they leave, and what stops them.

Thermodynamics

Simulator · Thermodynamics Heat Engine and Carnot Cycle Simulator Run a gas around a thermodynamic cycle and read the work off the enclosed area. Simulator · Thermodynamics Kinetic Theory Gas Simulator Atoms in a box, with the gas law measured rather than assumed. Simulator · Thermodynamics States of Matter Simulator Atoms that freeze, melt and evaporate as you heat and cool them.

Maths & Data

Simulator · Maths & Data Riemann Sum and Integral Explorer Watch rectangles converge on an integral, and compare how fast each rule gets there. Simulator · Maths & Data Derivative and Tangent Line Explorer Sweep a tangent along a curve and watch the derivative draw itself underneath, one gradient at a time.

Every simulator here runs a real model rather than an animation of one. The projectile integrates its own motion, the gas simulator tracks a few hundred hard discs and reads the temperature back out of their speeds, and the membrane simulator solves the Goldman equation for whatever permeabilities you set. Change an input and the behaviour changes because the physics changed, not because a curve was redrawn to look different.

That distinction matters most where the result is surprising. Two carts colliding, a sum converging on an integral, a circuit ringing rather than settling: those are worth watching precisely because the outcome is not what a first guess suggests, and an animation that was drawn to illustrate a conclusion cannot surprise anyone.

All of them read their state from the address bar, so any configuration you reach is a link you can send to someone. All of them can be embedded in a lesson page or a blog. None of them need an account.

What the numbers on screen are for

Each simulator prints the quantities the model is actually working with, not a summary of them. A pendulum shows its period and its energy per unit mass; a heat engine shows the efficiency alongside the Carnot limit it cannot beat. The point is that you can check them. Take the pendulum period, put the same length and gravity into the formula by hand, and the two agree, which is the only reason to trust the animation next to it.

Where a model has a limit, it says so rather than quietly extrapolating past it. The small-angle approximation for a pendulum is flagged when the amplitude leaves the range where it holds, and the ideal gas simulator will tell you when the density it is asked for stops being ideal. A tool that keeps answering confidently outside its own validity is worse than one that stops.

Using these in a lesson

Two buttons under each simulator are for this. “Copy link to this result” gives a link that reproduces exactly the state on screen, and “Embed” gives the code to put the simulator on your own page, opening on that same state. The link is the useful one for setting work, because you can pose a question by pointing at a specific configuration rather than describing it in words and hoping it gets reproduced.

The embed is free to use. Please keep the caption link underneath it, which gives your readers a way to open the full page; you are free to mark it nofollow if your site’s policy calls for it.

Reduced motion, and reading these without the animation

If your system asks for reduced motion, the simulators do not autoplay. Each one chooses a still frame that is worth looking at instead of stopping at frame zero: the projectile jumps to the end of its flight so the whole arc is visible, and the pendulum draws itself at rest. Play is always available if you want it.

Every scene also carries a written description, and the readouts are real text rather than pixels, so the numbers are reachable by a screen reader and can be copied out.