Readytorun

The STP Sensitivity to Initial Conditions program shows 11 particles in a line with the same velocity. You can perturb the system slightly and observe how sensitive the trajectory is to a small change. The default perturbation strength is 1.00001. STP SensitivityToInitialConditions is part of a...

The RandomWalk1D program simulates a random walk in one dimension for steps of unit length and equal time intervals. The default number of steps is N = 16 and the probability of going right or left at any step is the same (the probability p of going to the right for a single step is 0.5)....

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

The Ejs Three Charged Particles model displays three charged objects, one at each corner of an equilateral triangle. The charges have different magnitudes - your job is to rank the charges based on their magnitudes, from largest to smallest. You can drag the charges around to see the effect on...


Platforms: Mac

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

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

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

The EJS Molecular Dynamics Demonstration 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...


Platforms: Mac

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

The Noon Shadow model shows the geometry of the shadow cast by a gnomon at noon. Users can change the orientation of the gnomon as well as its latitude. The height of the gnomon and its shadow length are displayed in Earth radius units. It is a supplemental simulation for an article by Barbara...


Platforms: Mac

The Ejs Non-Newtonian Orbit model displays the dynamics of a mass orbiting a much larger mass subject to non-Newtonian gravity. The simulation displays the motion of the smaller mass and the effective potential energy diagram. The initial energy of the system can be changed via textbox and the...


Platforms: Mac

The Ejs Duffing Phase 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 evolution of a group of oscillators with similar initial parameters on a phase...


Platforms: Mac

The Ejs Duffing Chaos 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 two solutions with different initial positions and a plot of phase. The evolution...


Platforms: Mac

The Ejs Orbiting Mass with Spring Force model displays the frictionless dynamics of a mass constrained to orbit on a table due to a spring. The simulation displays the motion of the mass as well as the effective potential energy. The initial velocity, k/m, and the proper or natural length of the...


Platforms: Mac

The Ejs Spinning Hoop model displays the model of a bead moving along a hoop which is spinning about its vertical diameter with constant angular velocity ?. Friction is negligible. The simulation displays the motion of the bead as well as a plot of angle vs. time for the bead. The angular...


Platforms: Mac

The Ejs Duffing Poincare 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 Poincare plot. The evolution parameters can be changed via textboxes....


Platforms: Mac

The Ejs TPT Ladder Demonstration model displays the statics and dynamics of a ladder leaning against a wall. The standard (textbook) statement of this problem assumes that there is no frictional force between the wall and the ladder, but a frictional force between the ground and the ladder. In...


Platforms: Mac

The Thin Film Interference model investigates reflection and transmission of light through a thin film. The user can change the thickness and index of refraction of the thin film as well as the incident light wavelength. The Thin Film Interference Model was created using the Easy Java...


Platforms: Mac

The EJS Ballistics and Orbits model displays ballistic trajectories near the Earth. The model shows the trajectory with respect to the inertial coordinate system and the trajectory as seen from a point of view that is co-rotating with the Earth. You can examine and modify this simulation if you...


Platforms: Mac

The Ejs Orbiting Mass with Constant Force model displays the dynamics of an orbiting mass due to a constant force (a linear potential energy function). The simulation displays the motion of the mass as well as the effective potential energy. The initial conditions can be changed by dragging the...


Platforms: Mac