Readytorun

The Ejs Free Fall model displays the dynamics of a ball dropped near the surface of Earth onto a platform. The initial conditions for the ball are zero initial velocities in the x and y directions. The coefficient of restitution for the ball's collision with the platform is less than one. The...

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...

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

The Ejs Coupled Oscillators and Normal Modes model displays the motion of coupled oscillators, two masses connected by three springs. The initial position of the two masses, the spring constant of the three springs, the damping coefficient for each mass, and the driving force and driving force...


Platforms: Mac

The QM Position Measurement program displays the time evolution of the position-space wave function and can be used to simulate the quantum-mechanical measurement of position. The default wave function is an equal-mix four-state superposition in the infinite square well. QM Position Measurement...


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 Ejs Doppler Effect model displays the detection of sound waves from a moving source and the change in frequency of the detected wave via the Doppler effect. In addition to the wave fronts from the source a graph depicting the time of emission and time of detection of each of the wave fronts...


Platforms: Mac

The Rectangular Well model displays the 2D energy eigenstates of a particle trapped in a very deep two-dimensional rectangular well. Because the Schr?*A*dinger equation for this system is separable into one-dimensional infinite square well Hamiltonians, the solution can be expressed as a product...


Platforms: Mac

The EJS Magnetic Bar Field Model shows the field of a bar magnet and has a movable compass that reports the magnetic field values. The bar magnet model is built by placing a group of magnetic dipoles along the bar magnet. You can modify this simulation if you have Ejs installed by right-clicking...


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 Phase Space Plotter model displays the dynamics of an ensemble of pendula or simple harmonic oscillators in phase space (velocity versus position). Friction is initially set to zero but can be changed via a textbox as can the number of elements in the ensemble. For the pendulum ensemble,...


Platforms: Mac

The Ejs Hard Disk Gas model displays a two-dimensional gas made out of hard disks. Particles are initialized with a speed v=1 in a random direction and move with constant velocity until a collision occurs. You can modify this simulation if you have Ejs installed by right-clicking within the plot...


Platforms: Mac

The Phase Matters package is a self-contained file for the teaching of phase and time evolution in quantum mechanics. The file contains ready-to-run OSP programs and a set of curricular materials. The material focuses on when and how, for arbitrary quantum-mechanical states, the phase of the wave...


Platforms: Mac

The QM Wigner program displays the time evolution of the position-space wave function and the associated quasi-probability distribution in phase space via the Wigner function. The default wave function is a Gaussian wave packet in a harmonic oscillator. Additional states and other potential...


Platforms: Mac

The STP LJ2DMetropolis program is a Monte Carlo simulation of Lennard-Jones particles in two dimensions in contact with a heat bath. The default initial condition is a rectangular configuration of N=64 particles in a box of length L = 18 and a temperature T= 1. STP LJ2DMetropolis is part of a...


Platforms: Mac

The Ejs Lagrange Top model displays the motion of a heavy symmetric top under the effect of gravity. The top has an initial angular speed that provides the precessional, nutational, and rotational speeds. The ratio of Lz to Lx can be set via slider and the initial angular position and angular...


Platforms: Mac

The EJS Molecular Dynamics model is constructed using the Lennard-Jones potential truncated at a distance of 3 molecular diameters. The motion of the molecules is governed by Newton's laws, approximated using the Verlet algorithm with the indicated time step. For sufficiently small time steps dt,...


Platforms: Mac

The Ejs Foucault Pendulum model displays the dynamics of a Foucault pendulum. The simulation is designed to show the dynamical explanation of why precession of the Foucault pendulum is slower at lower latitudes. The simulation shows simultaneously the motion with respect to the inertial...


Platforms: Mac

The STP Hard Disks Metropolis program is a Monte Carlo simulation of hard disks in two dimensions. The default initial condition is a rectangular configuration of N=64 particles in a box of length L = 40. You can slowly increase the density of the gas (by setting the minimum scale length between...


Platforms: Mac