Maxwell

Speed Distribution

Instantaneous Average

Description

Although the particles in this simulation start with the same initial velocity, collisions quickly produce what appear to be random values.  An instantaneous histogram of the particle speeds begins to reveal the underlying order.  If this histogram is averaged over may seconds, the well know Maxwell-Boltzmann speed distribution is obtained.

Questions

Answers

Features of this Script

Physlets can contain more than one data source.  For example, most molecular dynamics Physlets contain a data source that calculates the histogram of the particle speeds.  In the first script, the histogram data source passes its values directly to the data graph. 

hid=document.molecular.getHistogramID(20,0.0,10.0);
gid=document.datagraph.getGraphID();
.
document.molecular.makeDataConnection(hid,gid,1,"v","n");

In the second script, the histogram data is passed to an intermediate applet, a histogram data filter.  This data filter accumulated the data, thereby showing the time averaged speed distribution.

hid=document.molecular.getHistogramID(20,0.0,10.0);
gid=document.datagraph.getGraphID();
fid=document.histogram.getID();
.
document.molecular.makeDataConnection(hid,fid,1,"v","n");
document.histogram.makeDataConnection(fid,gid,1,"x","y");

Required Resources

Jar files:  DataGraph4_.jar, Molecular4_.jar, STools4.jar
Images:  none

Credits

Script by Wolfgang Christian
Questions by Wolfgang Christian.
Java applets by Wolfgang Christian.