Easy Java Text Scrollers

The EJS Faraday Loop Changing Field Model shows the induced emf in a changing external magnetic field. You can control the frequency, magnitude and type of variation in the external field as you would in the laboratory when using a function generator to produce current in a large coil. You can...

The Double Slit Wave-Particle Duality Model demonstrates how matter and light display both wave- and particle-like properties in single and double slit experiments. The simulation shows a detector screen placed behind an aperture with one or two open slits. Particles (electrons or photons) pass...

The Levenberg-Marquardt Fitting of Nuclear Decay Model demonstrates how EJS can be used to fit experimental data. In this simulation, nuclear decay data are used to provide a simple example, but this same process can be applied to any type of data. The sum of squared deviations is minimized but...


Platforms: Mac

The Wang-Landau algorithm, also called the flat-histogram algorithm, can be used to calculate the density of states of a microscopic system. In this simulation, the Wang-Landau algorithm is used to calculate the density of states for a two-dimensional Ising ferromagnet with periodic boundary...


Platforms: Mac

This simulation allows students to compare the motion of free falling objects with and without the influence of air resistance. Air resistance is the result of collisions of the object's leading surface with air molecules. On Earth, objects falling through the air usually encounter some sort of...


Platforms: Mac

The Circular Well Superposition simulation displays the time evolution of the position-space wave function in an deep 2D circular well. The default configuration shows the first excited state with zero angular momentum. Additional eigenstates can be added using a button in the eigenstate...


Platforms: Mac

The EJSMagnetic Field from Loops model computes the B-field created by an electric current through a straight wire, a closed loop, and a solenoid. Users can adjust the vertical position of the slice through the 3D field. The Magnetic Field from Loops model was created using the Easy Java...


Platforms: Mac

The Lagrangian Pendulum Spring model asks students to solve the Lagrangian for a spring-pendulum and then develop a model of it. It is distributed as a ready-to-run (compiled) Java archive. Double-clicking the ejs_CM_Lagrangian_pendulum_spring.jar file will run the program if Java is installed....


Platforms: Mac

The Kicked Rotor model shows the dynamics of a rotating bar (rotor) that is kicked periodically. This model is also known as the standard map or the Chirikov-Taylor map. Each impulsive kick changes the angular momentum of the rotor instantaneously and the bar rotates uniformly between kicks....


Platforms: Mac

The Newton's Law of Cooling model computes the temperature of an object of mass M as it is heated by a flame and cooled by the surrounding medium. The model assumes that the temperature T within the object is uniform. This lumped system approximation is valid if the rate of thermal energy...


Platforms: Mac

The EJS Radioactive Decay Distribution Model simulates the decay of a radioactive sample using discrete random events. It displays the distribution of the number of events (radioactive decays) in a fixed time interval. If each event is assumed to occur independently and spontaneously with a...


Platforms: Mac

The Ejs Harmonics and Fourier Series model displays the sum of harmonics via a Fourier series to yield a new wave. The amplitude of each harmonic as well as the phase of that harmonic can be changed via sliders. In addition, several pre-set functions can be chosen to display. You can modify this...


Platforms: Mac

The Falling Slinky model approximates a slinky using twenty masses connected with light springs. The slinky is suspended from one end and released. Two actions will occur simultaneously when it is released hanging at rest from its equilibrium position - it will fall and it will collapse. What...


Platforms: Mac

RC Circuit models the dynamical behavior of a voltage source attached in series to a resistor and capacitor. The source voltage can be chosen to be either a 10 volt sinusoidal or square wave with an adjustable frequency. Users can examine and change the model if they have Ejs installed. The RC...


Platforms: Mac

The Kepler System model simulates Kepler's final theory of planetary motion. In this theory the planets orbit in ellipses with Sun at one focus (Kepler's First law). These elliptical orbits are not necessarily all in the same plane. A line from Sun to the planet sweeps out equal areas in equal...


Platforms: Mac

The Ejs Celestial Globe model simulates the Two Sphere Universe theory of the Ancient Greeks. This theory supposes the stars to be fixed on the surface of a Celestial Sphere, with the spherical Earth at the center of this sphere. The simulation shows the motion of Sun and stars in this model, as...


Platforms: Mac

The Ejs N-body Orbits model displays the dynamics of three to five identical masses orbiting each other subject to Newtonian gravity. The simulation displays the periodic orbital motion of the masses. The initial configuration of the system can be changed via slider. You can modify this...


Platforms: Mac

The Gaussian Wave Packet: Step Scattering model simulates the time evolution of a free Gaussian wave packet in position space when it is incident on a potential energy step. The position-space wave functions are depicted using three colors on the graph: black which depicts the absolute square of...


Platforms: Mac

The Ejs Circumnavigating Pendulum model displays the dynamics of a mechanical oscillator in uniform circular motion. The mechanical oscillator is free to move in two directions. This 2-dimensional simulation displays all the dynamical features of the Foucault pendulum, except for the dependency...


Platforms: Mac

The 3-D Hydrogen Atom Probability Densitites model simulates the probability density of the first few (n = 1, 2, and 3, and associated l and m values) energy eigenstates for the Hydrogen atom (the Coulomb potential). The main window shows the energy level diagram for the solutions to the Coulomb...


Platforms: Mac