Double Rayleigh Model
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
License: Freeware | Size: 1.29 MB | Download (34): Celestial Globe Model Download |
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
License: Freeware | Size: 1.34 MB | Download (37): N-body Orbits Model Download |
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
License: Shareware | Cost: $0.00 USD | Size: 737.28 KB | Download (36): Rectangular Well Model Download |
The Ejs Orbiting Mass on a Table 3D model displays the frictionless dynamics of two masses that are attached via a string through a hole in a horizontal table. Mass m moves on the table in two dimensions while mass M hangs vertically and just moves up and down. The simulation allows displaying...
Platforms: Mac
License: Freeware | Size: 1.67 MB | Download (40): Orbiting Mass on a Table 3D Model Download |
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
License: Freeware | Size: 92.16 KB | Download (39): Magnetic Bar Field Model Download |
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 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
License: Shareware | Cost: $0.00 USD | Size: 1.19 MB | Download (37): Hard Disk Gas Model 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 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 Inertial Oscillation model displays the motion of a particle moving over the surface of an oblate spheroid. The spheroid is flattened to an ellipsoid of revolution because it is rotating, just as the Earth is flattened because it is rotating. The particle is confined to motion along the...
Platforms: Mac
License: Freeware | Size: 1.05 MB | Download (36): Inertial Oscillation Model Download |
The EJS Equinox Precession model illustrates the Copernican theory of Earth's orbit around the sun. The top window shows a view from outside the celestial sphere. The simulation shows the moving Earth along with its axis or rotation and the line of sight from Earth, through Sun, to the Celestial...
Platforms: Mac
License: Freeware | Size: 1.32 MB | Download (35): Equinox Precession 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 Ejs Group Velocity model displays the time evolution for the superposition of two traveling waves of similar wave numbers and frequencies. The simulation allows an arbitrarily superposition of two waves for the study of group and phase velocity. The amplitude, wave number, and angular...
Platforms: Mac
License: Shareware | Cost: $0.00 USD | Size: 1.32 MB | Download (38): Group Velocity 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 |