Here is a EJS version of the simulation similar to the one at

The force for the particle is assumed to be $\vec{F}=-b\vec{V}-\vec{g}$.
You can adjust parameter b and restitution coefficient with slider.

The id slider control which particle will be modified when x,y,z,vx,vy,vz are adjusted with slider.

You will find "size effect" when b>0. i.e. smaller particle slow down faster.

Click [eye]

/htdocs/ntnujava/ejsuser/2/users/ntnu/fkh/particlesingravity3D_pkg/particlesingravity3D.propertiesFull screen applet or Problem viewing java?Add 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(1541.2kB):double click downloaded file to run it. (6 times by 6 users) , Download EJS source (2 times by 2 users) View EJS source

[/eye] to view simulation.