This Demonstration shows the path of a multiply reflected superball in a horizontal channel (ignoring gravity). At each reflection, the energy and the angular momentum of the ball are conserved, but due to friction, translational and rotational energy can be converted into each other. The initial position of the ball is the red point and the final position is the blue point

The graphic is scaled so that all reflections are shown and angles are not distorted.

Contributed by: Michael Trott with permission of Springer

The moment of inertia of the ball is assumed to be variable. The initial value is the one for a solid ball. Balls with a radius-dependent mass density will have other moments of inertia.