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# PhET Simulations

The PhET Interactive Simulations project at the University of Colorado Boulder creates free interactive math and science simulations. PhET sims are based on extensive education research and engage students through an intuitive, game-like environment where students learn through exploration and discovery.

• PhET: Atomic Interactions
Explore the interactions between various combinations of two atoms. Observe the the total force acting on the atoms or the individual attractive and repulsive forces. Customize the attraction to see how changing the atomic diameter and interaction strength affects the interaction.
• PhET: Balancing Act
Play with objects on a teeter totter to learn about balance. Test what you've learned by trying the Balance Challenge game.
• PhET: Balloons and Static Electricity
Why does a balloon stick to your sweater? Explore the charges in the sweater, balloons, and the wall as you investigate!
• PhET: Bending Light
Explore bending of light between two media with different indices of refraction. See how changing from air to water to glass changes the bending angle. Play with prisms of different shapes and make rainbows.
• PhET: Build an Atom
Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!
• PhET: Capacitor Lab - Basics
Explore how a capacitor works! Change the size of the plates and the distance between them. Change the voltage and see charges build up on the plates. View the electric field, and measure the voltage. Connect a charged capacitor to a light bulb and observe a discharging RC circuit.
• PhET: Charges and Fields
Arrange positive and negative charges in space and view the resulting electric field and electrostatic potential. Plot equipotential lines and discover their relationship to the electric field. Create models of dipoles, capacitors, and more!
• PhET: Circuit Construction Kit: DC
Experiment with an electronics kit! Build circuits with batteries, resistors, light bulbs, and switches. Determine if everyday objects are conductors or insulators, and take measurements with an ammeter and voltmeter. View the circuit as a schematic diagram, or switch to a lifelike view.
• PhET: Circuit Construction Kit: DC - Virtual Lab
Do you like Circuit Construction Kit: DC, but want to use only in-line ammeters? This is the sim for you! Experiment with an electronics kit. Build circuits with batteries, resistors, light bulbs, and switches. Determine if everyday objects are conductors or insulators, and take measurements with a lifelike ammeter and voltmeter. View the circuit as a schematic diagram, or switch to a lifelike view.
• PhET: Color Vision
Make a whole rainbow by mixing red, green, and blue light. Change the wavelength of a monochromatic beam or filter white light. View the light as a solid beam, or see the individual photons.
• PhET: Energy Skate Park - Basics
Learn about conservation of energy with a skater gal! Explore different tracks and view the kinetic energy, potential energy and friction as she moves. Build your own tracks, ramps, and jumps for the skater.
Investigate Faraday's law and how a changing magnetic flux can produce a flow of electricity!
• PhET: Forces and Motion: Basics
Explore the forces at work when pulling against a cart, and pushing a refrigerator, crate, or person. Create an applied force and see how it makes objects move. Change friction and see how it affects the motion of objects.
• PhET: Friction
Move the Chemistry book and observe what happens. Note that the interactive elements in this sim have simple description that can be accessed using a screen reader.
• PhET: Gravity and Orbits
Move the sun, earth, moon and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it!
• PhET: Gravity Force Lab
Visualize the gravitational force that two objects exert on each other. Adjust properties of the objects to see how changing the properties affects the gravitational attraction.
• PhET: Hooke's Law
Stretch and compress springs to explore the relationships between force, spring constant, displacement, and potential energy! Investigate what happens when two springs are connected in series and parallel.
• PhET: John Travoltage
Play with John’s foot and arm to explore when he gets a zap!
• PhET: Masses & Springs
A realistic mass and spring laboratory. Hang masses from springs and adjust the spring stiffness and damping. You can even slow time. Transport the lab to different planets. A chart shows the kinetic, potential, and thermal energy for each spring.
• PhET: Molecules and Light
Adjust light source slider and begin your observations of how different molecules react to different light sources. Note that the interactive elements in this sim have simple description that can be accessed using a screen reader.
• PhET: Ohm's Law
See how the equation form of Ohm's law relates to a simple circuit. Adjust the voltage and resistance, and see the current change according to Ohm's law.
• PhET: Pendulum Lab
Play with one or two pendulums and discover how the period of a simple pendulum depends on the length of the string, the mass of the pendulum bob, the strength of gravity, and the amplitude of the swing. Observe the energy in the system in real-time, and vary the amount of friction. Measure the period using the stopwatch or period timer. Use the pendulum to find the value of g on Planet X. Notice the anharmonic behavior at large amplitude.
• PhET: Projectile Motion
Blast a car out of a cannon, and challenge yourself to hit a target! Learn about projectile motion by firing various objects. Set parameters such as angle, initial speed, and mass. Explore vector representations, and add air resistance to investigate the factors that influence drag.
• PhET: Resistance in a Wire
Observe changes to the equation and wire as you play with the resistivity, length, and area sliders.
• PhET: Rutherford Scattering
How did Rutherford figure out the structure of the atom without being able to see it? Simulate the famous experiment in which he disproved the Plum Pudding model of the atom by observing alpha particles bouncing off atoms and determining that they must have a small core.
• PhET: States of Matter
Watch different types of molecules form a solid, liquid, or gas. Add or remove heat and watch the phase change. Change the temperature or volume of a container and see a pressure-temperature diagram respond in real time. Relate the interaction potential to the forces between molecules.
• PhET: States of Matter - Basics
Heat, cool and compress atoms and molecules and watch as they change between solid, liquid and gas phases. Heat, cool and compress atoms and molecules and watch as they change between solid, liquid and gas phases.
• PhET: Under Pressure
Explore pressure under and above water. See how pressure changes as you change fluids, gravity, container shapes, and volume.
• PhET: Wave Interference
Make waves with a dripping faucet, audio speaker, or laser! Add a second source to create an interference pattern. Put up a barrier to explore single-slit diffraction and double-slit interference.
• PhET: Wave on a String
Explore the wonderful world of waves! Even observe a string vibrate in slow motion. Wiggle the end of the string and make waves, or adjust the frequency and amplitude of an oscillator.