Alright, so I'm probably not going to finish the physics. Anyone else, feel free to do it, although you were already rightly allowed to.
I don't know if I could (my physics and maths skills are somewhat like early high-school level, and I don't have an immediate use for such a plugin. But in the middle term, I might consider it after being done with my currents milestones.)
Could you upload what you already have done so far as a base to work upon please ?
I'll make smaller things.. actually there's quite a few 'big' ideas (3d objects, among others) that I can easily see myself being motivated to make over physics for some reason.
3D objects would require WebGL, right ?
How would you consider incorporating this into C2 and the canvas object ?
I found the J3D (javascript) library which demos are pretty impressive.
Anyway, looking forward for such a plugin.