Easy Java Simulations 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...

The Diffusion Limited Aggregation in Continuous 2D Space Model simulates the formation of a cluster using a random-walk process called "diffusion limited aggregation" (DLA). The cluster formed by this process is an example of a fractal, and the simulation can be extended to calculate and analyze...

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 Ejs Wave Function Plotter model displays a one-dimensional wave function u(x,t) depicting a disturbance at position x and time t. The disturbance can be mass density, pressure, or electric field depending on the physical context. The default wave function is sinusoidal but any other analytic...


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 EJS Cellular Automata (Rule 90) model displays a lattice with any one of a finite number of states which are updated synchronously in discrete time steps according to a local (nearby neighbor) rule. Rule 90 is a specific nearby neighbor rule following the classification scheme developed by...


Platforms: Mac

The Binomial Coefficient model displays the number of ways k objects can be chosen from among n objects when order is irrelevant. This number is known as a binomial coefficient and can be used to predict the the flipping of n coins with equal probability of heads and tails. The Binomial...


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 EJS Kac Model simulates the relaxation of a gas to equilibrium by randomly selecting and then colliding gas molecules but without keeping track of the molecules' positions. As long as the collisions are consistent with spatial isotropy, the Boltzmann speed distribution will emerge. You can...


Platforms: Mac

This computer model allows students to split a vector into its components and practice finding the magnitude and direction. In addition, it offers a "Find components" mode, where magnitude and direction of the vector are given and the student's task is to find the x-component and the y-component...


Platforms: Mac

This interactive simulation allows students to explore how the relative position of Sun, Earth, and Moon produce the various phases of the moon, as seen from the Earth. The main window displays Earth (at the center) and Moon, with a circle tracing out Moon's orbit. Sun is far to the right in this...


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 Duffing Oscillator model computes the solutions to the non-linear Duffing equation, which reads, x'' + 2?zN*x' - x (1 - x2) = f cos(?Ya*t), where each prime denotes a time derivative. The simulation displays the solution as well as the phase space and Poincare plots, and energy diagram....


Platforms: Mac

The EJS Electric Field: What is Wrong? Package is a collection of models for electrostatics with errors intentionally built into each model. Users can move charges around and see the force, observe the electric field generated by charge configurations, and observe the motion of test particles in...


Platforms: Mac

The Partitioned Box program displays the number of particles on one half of a box as a function of time after a small hole is made in the partition dividing the box in half. The purpose of this simulation is to gain insight into the tendency of macroscopic systems to approach a well defined...


Platforms: Mac

This interactive simulation shows an airplane flying at constant horizontal velocity preparing to drop relief supplies to a small island. As captain of the plane, the student must first calculate the release point for dropping the package. As the simulation runs, press the red "+" button at the...


Platforms: Mac

This is a standards-based simulation for grade level 6-9, developed to help students visualize how total energy is conserved in a simple pendulum. It depicts a child swinging on a swing suspended from a stationary point. Students can drag the swing to different heights, then activate the motion....


Platforms: Mac

The Point Charge Forces in One-Dimension model investigates the electric force that one charged particle exerts on another. It is a very simple representation that promotes understanding of Coulomb's Law in three ways: First, students can set the amount of charge on each particle and view vector...


Platforms: Mac

This interactive simulation allows students to explore the concept of electric field in a 2-dimensional situation. Users can place one to five charged particles on the field and move a test charge around the plane. A grid of field vectors can also be activated to show the direction of the...


Platforms: Mac