еще кое-что об ударе

[Oleg Zubelevich]

http://www.rpi.edu/dept/phys/courses/PH ... erBall.pdf

"A perfectly rough ball which conserves kinetic energy behaves in such an unexpected way that it is difficult to pick up after it has bounced twice upon the floor, and, more bizarre, it returns to the hand on being thrown to the floor in such a way that it bounces from the underside of a table."