I want to study if particles that have some sort of affinity for each other (they stick together when they touch) collide more often than particles that don't have any affinity.[/quote]

Are you trying to compare two different cases: in different system?
1. system A: particles which stick together when they touch.
2. system B: particles which collide with each other when they touch.

If there are two different kinds of particles A and B, then they are three different cases
1. A and A touch
2. B and B touch
3. A and B touch
It is more than two cases.

Model for the following simulation : There are two kind of particles A,B
When same kind of particle touch, they will stick together and become a bigger particle (momentum is conserved but energy is not conserved).
Elastic collision occurs when different kind of particle touch each other (energy and momentum are conserved).

The energy is not conserved if two particles stick together.

translate strings in simulation to different language format before download
Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
Download EJS jar file(1477.8kB):double click downloaded file to run it. (2 times by 2 users) , Download EJS source (1 times by 1 users) View EJS source