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top spin super ball



A bouncing ball could be spinning so rapidly that its tangential
velocity at the point of impact could be in a direction opposite to
its CM motion.


In that case, the force exerted on the ball by the floor would be in
the forward direction. This would speed up the cm motion, and slow
down the rotation. This could turn a high, short, spinning bounce
into a long bounce with litle spin.

On the next bounce, the ball might be rotating slowly enough that its
tangential velocity on impact could be in the direction of motion (if
the ball were not rotating at all, this would definitely be the
case). In this situation, the force exerted on the ball by the floor
would be in the backward direction, slowing the cm motion and
speeding up the spin.

Mike


Mike Moloney, Dept of Physics & Applied Optics, Rose-Hulman Institute
of Technology

(812) 877 8302 http://www.rose-hulman.edu/~moloney