Hello Fu-Kwun Hwang. This really helped me. For my finals I chose to make a physics simulation application (in Game Maker 8.0) including brownian motion.

I have tried to get the final formula for v[sub]1[/sub]' with the first two equations but I just can't get it right. Could you maybe send me the the steps you took to get there? That would be great.

I also don't know how to calculate the component of a force (or other vector) in a certain direction so if you could help me with that I would really appreciate it.

Thanks in advance.

(I don't know if I double posted but I think my first post wasn't processed or something...)