Ejs Tpt Ladder Demojar
The EJS Angular Acceleration of a Contracting System model shows a mass and pulley system to illustrate what happens when a rotating system contracts. When the centripetal force has contracted a rotating system to half its initial radius then: (1) The tangential velocity has doubled, (2) The...
Platforms: Mac
License: Freeware | Size: 1.08 MB | Download (39): Angular acceleration of a Contracting System Model Download |
The Single-Slit Diffraction model simulates the diffraction pattern of light as it travels through a slit to a screen. The diffraction pattern is due to the difference in path length of the light from different parts of the slit as the light from the slit travels to the screen. The intensity of...
Platforms: Mac
License: Freeware | Size: 757.76 KB | Download (35): Single-Slit Diffraction 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 |
A mass constrained to move on a rotating hoop is an excellent mechanical model of first- and second-order phase transitions. Although the minimum of the potential energy curve corresponds to the bottom of the hoop at low rotation frequency, a spontaneous symmetry breaking (cusp catastrophe)...
Platforms: Mac
License: Freeware | Size: 1.6 MB | Download (35): Dynamics on a Rotating Hoop Model Download |
The EJS Electric Multipole Model of a point charge (monopole), a dipole, or a quadrupole can show either field vectors or the scalar potential (voltage). A slider changes the charge and a movable detector shows the electric field direction and magnitude or measures the potential. Detector values...
Platforms: Mac
License: Freeware | Size: 1.4 MB | Download (40): Electric Multipole Field Model Download |
The Ejs Great Circles model displays the frictionless motion of a particle that is constrained to follow the surface of a perfect sphere. The sphere rotates underneath the particle, but since there is no friction, and the sphere is perfectly spherical, the motion of the particle is not influenced...
Platforms: Mac
License: Freeware | Size: 10.24 KB | Download (39): Great Circles Model Download |
The EJS Slipping and Rolling Wheel Model shows the motion of a wheel rolling on a floor subject to friction. The simulation allows the user to change the initial translational and rotational velocities of the wheel, v and ?Ya*, the mass, radius, and mass distribution, R, m, and C of the wheel. By...
Platforms: Mac
License: Freeware | Size: 1.1 MB | Download (36): Slipping and Rolling Wheel Model Download |
The Falling Cup with Ball model shows a mass attached to the inside of a cup with a light spring. The cup is held upside down with the mass hanging out of the cup, then released from rest. What happens when the cup is released? 1. The mass will extend the spring, like a parachute, due to air...
Platforms: Mac
License: Freeware | Size: 10.24 KB | Download (42): Falling Cup with Ball Model Download |
The Ejs Wave Packet model displays the motion of an approximate wave packet. The simulation allows an arbitrarily wave packet to be created. The default dispersion relation, with the frequency equal to the wavenumber, results in a wavepacket that does not spread. The amplitude, maximum and...
Platforms: Mac
License: Freeware | Size: 1.4 MB | Download (41): Wave Packet Model Download |
The Ejs Superior Ptolemaic model illustrates Ptolemy's orbit for a superior planet. The model consists of a deferent circle, centered on a point some distance from Earth (at the eccentric point). Attached to this deferent is the center of another circle, the epicycle. The center of the epicycle...
Platforms: Mac
License: Freeware | Size: 1.08 MB | Download (37): Superior Ptolemaic Model Download |
The Driven Wave Machine model simulates a wave machine driven by a sinusoidal oscillator. The machine consists of horizontal bars welded to a torsion rod that is perpendicular to the bars. The simulation allows the user to change the number of bars, the drive frequency, and the boundary...
Platforms: Mac
License: Freeware | Size: 1024 KB | Download (36): Driven Wave Machine Model Download |
The Ejs Copernican System model illustrates Copernicus' system of planetary motions. The entire system is centered on the center of Earth's uniform, circular orbit. Sun is placed near, but not at, this center point. The orbit of each planet (other than Earth) consists of a deferent circle,...
Platforms: Mac
License: Freeware | Size: 1.07 MB | Download (37): Copernican System Model Download |
The Ejs Inferior Ptolemaic model illustrates Ptolemy's orbit for a inferior planet. The model consists of a deferent circle, centered on a point some distance from Earth (at the eccentric point). Attached to this deferent is the center of another circle, the epicycle. The center of the epicycle...
Platforms: Mac
License: Freeware | Size: 1.08 MB | Download (38): Inferior Ptolemaic Model Download |
The Magnet Falling Through Ring model shows the dynamics and the induced current when a magnet falls through a conducting ring. The current in the ring is computed by electromagnetic induction using to Faraday's law and the induced emf is proportional to the negative of the rate of change of...
Platforms: Mac
License: Freeware | Size: 1.31 MB | Download (37): Magnet Falling Through Ring Model Download |
The Local Coordinates model displays the position of a star in local (Altitude/Azimuth) coordinates. The horizon is shown along with the four cardinal directions (N, E, S, and W). The latitude of the observer is set at 35.5 degrees which sets the location of the north celestial pole (teal)...
Platforms: Mac
License: Freeware | Size: 10.24 KB | Download (36): Local Coordinates Model Download |
The Ejs Wave Representations model displays two representations of a sinusoidal wave on a string. One shows a movie of the wave traveling along a string - you can think of this representation as a sequence of photographs. The second representation is a plot of the displacement as a function of...
Platforms: Mac
License: Freeware | Size: 1.21 MB | Download (38): Wave Representations Model Download |
The Ejs Two Orbiting Masses with Relative Motion model displays the dynamics of two masses orbiting each other subject to Newtonian gravity. The simulation displays the motion of the masses in the inertial reference frame and the relative motion as seen from one of the masses. The initial energy...
Platforms: Mac
License: Freeware | Size: 1.38 MB | Download (36): Two Orbiting Masses with Relative Motion Model Download |
The Circular Well model displays the 2D energy eigenstates of a particle trapped in a very deep two-dimensional circular well. Because the Schr?*A*dinger equation for this system is separable into radial and angular differential equations, the solution can be expressed as a product of a Bessel...
Platforms: Mac
License: Freeware | Size: 1.24 MB | Download (39): Circular Well Model Download |