written by Todd Timberlake

The EJS Ideal Gas Expansion model simulates a two-dimensional ideal gas in a square box.   This simulation can be used as part of the activity described in "The Statistical Interpretation of Entropy: An Activity" by Todd Timberlake, to be published in The Physics Teacher.

In the model, the particles are initially all on the left (red) side of the box with otherwise random positions and random velocities (distributed according to a Maxwell distribution). Separate windows show the motion of the gas particles, a plot of the number of particles on each side versus time, and a histogram of the number of occurrences of a given number of particles on the left.  The user can modify this simulation if EJS is installed locally by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item.

EJS Ideal Gas Expansion model was created using the Easy Java Simulations (EJS) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.   Double clicking the ejs_entropy_IdealGasExpansion.jar file will run the program if  Java is installed.  EJS is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models.  Additional EJS models re available.  They can be found by searching ComPADRE for  Open Source Physics, OSP, or EJS.

• Download ejs_entropy_IdealGasExpansion.jar - 1374kb Java Archive File

Last Modified June 9, 2014

This file has previous versions.

The source code zip archive contains an XML representation of the EJS Ideal Gas Expansion Model.   Unzip this archive in your EJS workspace to compile and run this model using EJS.

• Download ejs_entropy_IdealGasExpansion.zip - 48kb Compressed File

Released under a This material is released under the GNU General Public License Version 2.

Published June 17, 2010
Last Modified June 9, 2014

This file has previous versions.