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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
License: Freeware | Size: 1.37 MB | Download (39): Duffing Oscillator Model Download |
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
License: Freeware | Size: 1.4 MB | Download (37): Phase Space Plotter Model Download |
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
License: Freeware | Size: 776.19 KB | Download (37): QM Wigner Download |
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
License: Freeware | Size: 40.96 KB | Download (44): Lennard-Jones 2D Metropolis Download |
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
License: Freeware | Size: 10.24 KB | Download (38): Lagrange Top Model Download |
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
License: Freeware | Size: 1.3 MB | Download (36): Molecular Dynamics Model Download |
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
License: Freeware | Size: 1.05 MB | Download (36): Foucault Pendulum Model Download |
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
License: Freeware | Size: 468.99 KB | Download (43): Hard Disks Metropolis Download |
The STP LJ Thermal Equilibrium program simulates the interaction between two systems of Lennard-Jones particles brought into thermal contact. The purpose of this simulation is to explore the nature of thermal equilibrium and the relation, if any, between the kinetic and potential energies of two...
Platforms: Mac
License: Freeware | Size: 492.54 KB | Download (36): Lennard-Jones Thermal Equilibrium Download |
The STP 1DIsing program is a Monte Carlo simulation of a one-dimensional Ising model in equilibrium with a heat bath at temperature T using the Metropolis algorithm. The default is N=64 spins up (s = 1) with no external field with heat bath temperature T=1. STP Ising1D is part of a suite of Open...
Platforms: Mac
License: Freeware | Size: 908.29 KB | Download (37): Ising 1D Download |
The Equatorial Coordinates model displays the position of a star in equatorial (Right Ascension/Declination --- RA/Dec) coordinates. The horizon is shown along with the four cardinal directions (N, E, S, and W). The Latitude slider changes the latitude of the observer which is shown by the change...
Platforms: Mac
License: Freeware | Size: 993.28 KB | Download (36): Equatorial Coordinates Model Download |
The Ejs Damped Driven Harmonic Oscillator Phasor model displays the motion of damped driven harmonic oscillator. The resulting differential equation can be extended into the complex plane, and the resulting complex solution is displayed with the real part of this solution being the position of...
Platforms: Mac
License: Freeware | Size: 1.38 MB | Download (36): Damped Driven Harmonic Oscillator Phasor Model Download |
The Ejs Quartic Oscillator model displays the motion of a bead moving without friction along a horizontal rod, while tied to two symmetric springs. Both the motion of the masses and the phase space plot are shown in the simulation. The natural length of the springs can be changed via textboxes....
Platforms: Mac
License: Freeware | Size: 1.34 MB | Download (37): Quartic Oscillator Model Download |
The Ejs Normal Modes on a Loaded String model displays the motion of a light string under tension between two fixed points. The string is also loaded with N masses located at regular intervals. The number of masses on the string can be changed via textboxes. You can modify this simulation if you...
Platforms: Mac
License: Freeware | Size: 1.35 MB | Download (40): Normal Modes on a Loaded String Model Download |
The Ejs Strange Harmonic Oscillator model displays the motion of two masses connected by a massless rigid rod and the masses may move without friction along two perpendicular rails in a horizontal table. The energy of the oscillator system can be changed via a slider. You can modify this...
Platforms: Mac
License: Freeware | Size: 1.43 MB | Download (41): Strange Harmonic Oscillator Model Download |
The Diffraction and Interference Model: Single and Double Slits shows diffraction and interference patterns from a single slit, double sources and double slits. The user can change the source wavelength, slit width, separation and distance between slit and screen. The Diffraction and...
Platforms: Mac
License: Freeware | Size: 808.96 KB | Download (38): Diffraction and Interference Model: Single and Double Slits Download |
The EJS Magnetic Multipole Field Model shows the field of a magnetic dipole or quadrupole with little compasses that indicate direction and relative field strength. A slider changes the angular orientation of the dipole and a movable compass shows the magnetic field direction and magnitude....
Platforms: Mac
License: Freeware | Size: 1.41 MB | Download (36): Magnetic Multipole Field Model Download |
The Ejs Waves and Phasors model displays the motion of a transverse wave on a string and the resulting phasors for the wave amplitude. The simulation allows an arbitrarily polarized wave to be created. The amplitude, period, phase velocity and number of phasors displayed can all be changed via...
Platforms: Mac
License: Freeware | Size: 1.32 MB | Download (37): Waves and Phasors Model Download |
The Ejs Resonance in a Driven String model displays the displacement of taut string with its right end fixed while the left end is driven sinusoidally. The driving frequency, amplitude, and the simulation's dt can be changed via text boxes and the motion can be further fine tuned by zooming in...
Platforms: Mac
License: Freeware | Size: 1.36 MB | Download (37): Resonance in a Driven String Model Download |
The Ejs Spring Pendulum model displays the model of a hollow mass that moves along a rigid rod that is also connected to a spring. The mass, therefore, undergoes a combination of spring and pendulum oscillations. The initial position and velocities, as well as the spring constant can be changed...
Platforms: Mac
License: Freeware | Size: 1.37 MB | Download (36): Spring Pendulum Model Download |