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Equilibrium Solutions

 

Once the orbits enter the trapping region, where do they go next? To answer this question we first solve for the motion of a ball bouncing on a stationary table. Then we will imagine slowly turning up the table amplitude.

If the table is stationary, then the high bounce approximation is no longer approximate, but exact. Setting A = 0 in the velocity map, equation (1.21), immediately gives

  equation802

Using the time map, tex2html_wrap_inline11734 , the coefficient of restitution is easy to measure [6] by recording three consecutive impact times, since

  equation808

To find how long it takes the ball to stop bouncing, consider the sum of the differences of consecutive impact times,

  equation814

Since tex2html_wrap_inline11736 , tex2html_wrap_inline11738 is the summation of a geometric series ,

  equation823

which can be summed for tex2html_wrap_inline11740 . After an infinite number of bounces, the ball will come to a halt in a finite time.

For these equilibrium solutions, all the orbits in the trapping region come to rest on the table. When the table's acceleration is small, the picture does not change much. The ball comes to rest on the oscillating table and then moves in unison with the table from then on.



Nicholas B. Tufillaro
Mon Mar 3 01:58:02 PST 1997