Thanks for explaining that. I understand now why that old billiard simulator program didn't work too well (-: And I suppose my answer to the basic question is, when the balls are "almost but not exactly" in alignment, the collisions overlap in time, because the speed of sound inside the balls is finite and the shock waves are all initiated before any of them travels very far. On Sat, Dec 11, 2010 at 15:34, Andy Latto <andy.latto@pobox.com> wrote:
[...] Of course, if the large ball started out slightly to the right of the origin, the collision order would be reversed, and we'd end up with the left ball moving left with speed 11V/9, the center ball moving right with speed 4V/9, and the right-hand ball moving right with velocity V/3.
[...] And what if the ball coming from the left has mass 1, the center ball has mass 3, and the left hand ball has mass 2, and again, the outer balls are approaching the origin with speed V from equal distances? [...] is there a third "simultaneous collisions", possibility, and if so, in the absence of symmetry, how do you calculate what happens? [...]
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