Compadre

The Partitioned Box program displays the number of particles on one half of a box as a function of time after a small hole is made in the partition dividing the box in half. The purpose of this simulation is to gain insight into the tendency of macroscopic systems to approach a well defined...

The STP EinsteinSolidHeatBath program simulates the exchange of energy between an Einstein solid and a heat bath. The purpose of this simulation is to determine the properties of a Einstein solid at different temperature T and to compare our results with analytical calculations of the...

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

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

The Ejs Spherical Pendulum model displays the dynamics of a spherical pendulum in three dimensions. The pendulum is initially displaced from equilibrium and the pendulum bob has zero initial velocity. You can modify this simulation if you have Ejs installed by right-clicking within the plot and...


Platforms: Mac

The Ejs Free Particle Wavepacket model displays the time evolution of a free (V = 0 everywhere) initial Gaussian wave packet in position and momentum space. The default wave functions have = 0 and = 0, respectively. The initial width of the position-space wavepacket can be changed with the...


Platforms: Mac

The Ejs Hard Disk Collision model displays a two-dimensional collision between two hard disks. The two disks have the same mass and only one mass is moving at the beginning of the simulation. The impact of the collision is offset by the impact parameter, b, which can be changed. The...


Platforms: Mac

The Ball in a Wedge model displays a ball confined to move between two walls that form a wedge shape. The ball undergoes elastic collisions with the walls of the wedge. The angle of the wedge can be changed by setting the angle with the text box or dragging one of the wedge walls. By clicking in...


Platforms: Mac

The GR Kerr Light program simulates the path of light in the equatorial plane near a rotating black hole using the Kerr metric. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the gr_kerr_light.jar file will run the program if Java is installed. The default setting is...


Platforms: Mac

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

The STP IdealGasNumberOfStates program numerically evaluates the number of states of an ideal gas and demonstrates finite size effects by plotting the actual number of states and the asymptotic expression. The default is two-dimensional system (d=2). STP IdealGasNumberOfStates is part of a suite...


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 Momentum Space package is a self-contained file for the teaching of the time evolution and visualization of energy eigenstates and their superpositions via momentum space in quantum mechanics. The file contains ready-to-run OSP programs and a set of curricular materials. The material focuses...


Platforms: Mac

The STP Entropy Einstein Solid program calculates the entropy of two Einstein solids that can exchange energy. The purpose of this calculation is to illustrate that the entropy is a maximum at thermal equilibrium. The default system is two Einstein solids with 50 particles each and total energy E...


Platforms: Mac

The Ejs Pendulum on an Accelerating Train model displays the model of a pendulum on an accelerating train. The problem assumes that the pendulum rod is rigid and massless and of length, L = 2, and the pendulum bob is of mass, m = 1. The initial pendulum angle and the initial velocity of the train...


Platforms: Mac

The GR Kerr Exploding program simulates orbits of objects released in an explosion in the equatorial plane of a rotating black hole using the Kerr metric. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the gr_kerr_exploding.jar file will run the program if Java is...


Platforms: Mac

The Ejs Harmonics and Fourier Series model displays the sum of harmonics via a Fourier series to yield a new wave. The amplitude of each harmonic as well as the phase of that harmonic can be changed via sliders. In addition, several pre-set functions can be chosen to display. You can modify this...


Platforms: Mac

The EJS Electric Field: What is Wrong? Package is a collection of models for electrostatics with errors intentionally built into each model. Users can move charges around and see the force, observe the electric field generated by charge configurations, and observe the motion of test particles in...


Platforms: Mac

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

The EJS Earth Orbit 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 Sphere....


Platforms: Mac