File Archive Double
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 (40): 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 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 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 (36): Equinox Precession 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 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 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 |
The Pendulum Motion Model shows the motion of a simple pendulum. You can change the mass of the pendulum bob, the length of the string, the acceleration due to gravity, and the initial position of the pendulum. You can then see the resulting motion of the pendulum, as well as see bar graphs of...
Platforms: Mac
License: Freeware | Size: 1.41 MB | Download (35): Pendulum Motion Model Download |
The Ikeda Delay Differential Equation model shows the dynamics of a delay differential equation that depends on the value of the dynamical variable x(t) at a previous time x(t-?). Sprott shows that these systems provide elegant examples of chaos in systems that are too simple to exhibit chaos...
Platforms: Mac
License: Freeware | Size: 778.24 KB | Download (37): Ikeda Delay Differential Equation Model Download |
The Light and Shadow Model shows light that either passes through a mask with a hole in it, or it is blocked by an object, as it travels to a screen on the right. The user can turn on and off two light bulbs (red and blue) and drag the bulbs around the screen to change their positions....
Platforms: Mac
License: Freeware | Size: 757.76 KB | Download (34): Light and Shadow Model Download |
The Ejs Two Falling Rods model displays the dynamics of two rods which are dropped on a smooth table. In one case the end point on the table slides without friction, while in the other case it rotates about a pivot point. The simulation allows computing fall times and trajectories. The initial...
Platforms: Mac
License: Freeware | Size: 1.4 MB | Download (42): Two Falling Rods Model Download |
The EJS Waveguide model displays the motion of a traveling wave forced to move between two walls in a waveguide. The two walls are located at y = 0 and a, so that its normal modes are u(t,x) = A sin(n ?Y?* y/a) cos(k x - ?Ya* t) with n equal to a positive integer. The phase velocity and number of...
Platforms: Mac
License: Freeware | Size: 1.44 MB | Download (39): Waveguide Model Download |
The Ejs Three Current-Carrying Wires model is a ranking task exercise involving the ranking of the current magnitudes in three parallel current-carrying wires. The simulation displays the net force on each wire because of the other two wires. You can modify this simulation if you have Ejs...
Platforms: Mac
License: Freeware | Size: 1.16 MB | Download (42): Three Current-Carrying Wires Model Download |
The EM Radiation program displays the electric field vectors (in the x-y plane) and magnetic field contours (for the field in the z direction) calculated from the Lienard-Wiechert potentials for a charged particle. The default scenario shows the resulting radiation from a charged particle in...
Platforms: Mac
License: Freeware | Size: 621.57 KB | Download (34): EM Radiation Download |
The QM Momentum Measurement program displays the time evolution of the position-space wave function and can be used to simulate the quantum-mechanical measurement of momentum. The default wave function is an equal-mix four-state superposition in the infinite square well. QM Momentum Measurement...
Platforms: Mac
License: Freeware | Size: 71.68 KB | Download (36): QM Momentum Measurement Download |
The QM Momentum Space program displays the time evolution of the position-space wave function and the associated momentum-space wave function. Additional states and other potential energy functions can be specified using the Display | Switch GUI menu item. QM Momentum Space is one of 18 Open...
Platforms: Mac
License: Freeware | Size: 61.44 KB | Download (41): QM Momentum Space Download |