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A comment on Perfectly centered break of a perfectly aligned pool ball rack. Parent comment

Re:Perfectly centered break of a perfectly aligned pool ball... by rcthompson on Monday February 03, 2014 @02:41AM (#7169352)
Hmm. How does the elasticity model provide the additional constraint needed to give an unique solution?
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Re:Perfectly centered break of a perfectly aligned pool ball... by waqf on Monday February 03, 2014 @10:58AM (#7171283)
It provides a way to apportion the impulse between the two simultaneous collisions. It behaves as a differential equation because the instantaneous force in each collision depends (via the elasticity model) on the instantaneous velocities of the balls, which in turn depend on how much momentum has already been transferred.
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