Easy Java Text Scrollers

The Introductory Physics 2D (Projectile) Motion Lab program asks students to develop a model for a ball with projectile motion. It is distributed as a ready-to-run (compiled) Java archive. Double-clicking the ejs_intro_2DMotionLab.jar file will run the program if Java is installed. In order to...

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...

The Ejs Coin Rolling without Sliding on an Accelerated Platform model displays the dynamics of a coin rolling without slipping on an accelerated platform. The simulation displays the motion of the coin as well as the velocity vectors for the surface of the coin and the platform. The initial...


Platforms: Mac

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

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

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

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

The Driven Mass and Spring Mesh model displays the dynamics of a 2D array of masses coupled by springs and driven by a sinusoidal force. The model shows a time-dependent animation of the displacement or each mass. The driving force can be applied at a single point (shown in red) or uniformly at...


Platforms: Mac

The Young Two Slit Interference model simulates the interference pattern of light as it travels through two slits to a screen. This result was first described by Young who used the wave theory of light to describe the interference of light through two slits. The interference pattern is due to the...


Platforms: Mac

The Diffraction and Interference Model: Single and Double Slits shows diffraction and interference patterns from a single slit, double sources and double slits. The user can change the source wavelength, slit width, separation and distance between slit and screen. The Diffraction and...


Platforms: Mac

The Eratosthenes model displays the shadows cast by two gnomons (sticks) at different locations on Earth. For one gnomon, Sun is directly overhead (as would be the case if the gnomon was on the Tropic of Cancer at the summer solstice). The other gnomon is due north of the first gnomon. The sizes...


Platforms: Mac

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

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

The Ejs Transverse Wave model displays the motion of a transverse wave on a string. The simulation allows an arbitrarily polarized wave to be created. The magnitude of the components of the wave and the relative phase between the components of the wave can all be changed via sliders. You can...


Platforms: Mac

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

The Blackbody Radiation: Frequency and Wavelength model simulates the blackbody radiation curves of Planck both as a function of frequency and as a function of wavelength to allow for comparison of the two functions. The Planck radiation law can be derived both as a function of frequency and as a...


Platforms: Mac

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

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

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

The Orbits Within Spherical Galaxies model displays the two-dimensional trajectories of particles (stars) within a galaxy having a spherically symmetric mass distribution that heuristically approximates the distributions found in galaxies and bulges. The model uses a mass density proposed by...


Platforms: Mac