Irregular Bounces |
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During our bounce tests, we observed that
the synthetic ball seemed to bounce more
erratically compared to the leather ball.
The bounce test was then rearranged to test
this conjecture. The overhead sensor was
removed and replaced with two horizontal
position sensors (x and y directions). The
ball then passes through the sensor’s line
of sight twice (once on the way down and
once on the way back up) allowing us to
determine the difference in position. For
this experiment it was crucial that the ball
was released consistently without transverse
momentum. A release mechanism was created to
use suction hose to hold the ball. Turning
off the suction resulted in a near perfect
release.
Preliminary data shows an average horizontal
deviation (near the apex after the bounce)
of 15 mm for the leather ball, and 22 mm for
the synthetic ball, after bouncing off the
floor from a height of approximately 4 feet.
We speculate that the more uneven surface of
the strongly embossed synthetic balls is the
principal cause for the erratic bounces in
our tests. The surface of the leather ball
is far more consistently spherical and even.
In order to test this conjecture, the tests
have been repeated with the ball aligned to
drop onto a specific part of the surface,
allowing us to test each face of the ball.
The data from this additional test is still
being evaluated |
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