Sean Breheny wrote:
> Olin, also don't forget that bouncing causes higher peak force than a
> simple acceleration to a stop.

No, it doesn't.  I'm sure the card bounces some, but it still has to come to
a stop before reversing direction and going back up.  With perfectly elastic
materials, the decelleration and subsequent bouncing accelleration profiles
are symmetric.  With real materials, some energy will always be absorbed in
the compression of the materials during the decelleration phase.  This
energy won't be released during the bounce accelleration phase, making that
accelleration less than the initial decelleration.  After all, the card
won't bounce to anywhere near the original 10 feet, so obviously a good
chunk of the energy is absorbed by the material as it initially deforms.

If you think the accelleration due to bounce is higher than the initial
decelleration to zero, then you have think the material springs back more
quickly than it got initially compressed.  That's not likely, and any
inelasticity will actually make it go the other way and dissipate energy
too.

Resonance could lead to higher accellerations, but that has little to do
with bouncing.


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