Analyze the mix of hot and cold two-dimensional ideal gases with this tool. Cold Ideal Gases model simulates the mixing of hot and cold two-dimensional ideal gases 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.

This simulation uses Easy Java Simulations (Ejs) to model the mixing of hot and cold two-dimensional ideal gasses in a square box. One gas is intially confined to the left side of the box while the other gas is confined to the right side. An animation window shows the motion of the particles in the box, while an optional graph window plots the temperature of each side of the box (red=left, blue=right), which is determined by measuring the average KE of the particles on each side.
Controls:
1. Play/Pause: starts (or stops) the simulation.
2. Step: advances the simulation by one time step.
3. Reset: resets simulations with initial parameter values.
4. Reverse: reverses the velocity of all particles.
5. N (green): sets the number of particles in the green gas (up to 1000).
6. Temp. (green): sets the absolute temperature of the green gas (in units with Boltzmann's constant, the mass of the gas particles, and the length of the box equal to one).
7. N (black): sets the number of particles in the black gas (up to 1000).
8. Temp. (black): sets the absolute temperature of the black gas.
9. Temp. Plots: checkbox to show plots of the temperature of the left (red) and right (blue) sides of the box, using the average KE of particles on each side.
10. Speed (fps): slider to control the speed of the simulation, in terms of the number of frames displayed per second. Higher values make the simulation run faster.

You can modify this simulation if you have Ejs installed by right-clicking within the running simulation and selecting

In the model, one gas is initially confined to the left side of the box while the other gas is confined to the right side. An animation window shows the motion of the particles in the box, while an optional graph window plots the temperature of each side of the box, which is determined by measuring the average KE of the particles on each side. The initial number of particles and temperature on each side of the square can be changed and a button allows the user to reverse the particle velocities at any time. 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 Hot and Cold Ideal Gases 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_HotAndColdIdealGases.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 are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or EJS.

Requirements:
* Java

The license of this software is Free, you can free download and free use this graphing software.