NTNUJAVA Virtual Physics Laboratory

Easy Java Simulations (2001- ) => Examples for beginner who want to learn EJS => Topic started by: Fu-Kwun Hwang on June 13, 2010, 05:50:29 pm

Title: ParticlesAndWalls
Post by: Fu-Kwun Hwang on June 13, 2010, 05:50:29 pm
Particles and Walls 
This is perhaps the most complex and complete simulation that I have built as examples of use of Ejs. It simulates the electrical interaction of charged particles  , both positive and negative ones, among themselves and also with physical (non-charged) barriers or walls.
The user can build any configuration she is interested in and let the simulaton run. Of special interest is the visualization of the vector field generated by the charged particles and how it evolves dynamically.
I also included a visualization of the equipotential lines in the plane and of the potential in 3D. Just to show some of the visualization capabilities of Ejs.
The minimum and maximum of the potential are recomputed every time you switch on and off the visibility of the contour, so, when adding new particles, it is a good idea to hide the contour, add the particles, let the simulation play for a while, until a more or less stable situation has been reached, and then show the contour.
Please notice that (except when running as an applet) you can prepare and save different configuration of particles and walls. These configuration can be read later on by your students (even when running as an applet).
There are a lot of possible activities, but my favourite one is to build a closed wall, place inside a number of charges of the same sign and let the simulation run.
From time to time, freeze the particles and you will get with a final configuration in which all particles are at the walls.
Then, place a new one in the middle and see what happens. Relate this with applicable theory...

Author : Francisco Esquembre
 Date : February 2002
Title: Re: ParticlesAndWalls 3D
Post by: Fu-Kwun Hwang on June 13, 2010, 05:54:48 pm
The same simulation in 3D
Click [eye][ejsapplet][/eye] to view the simulation.