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Re: 9-11 Wackos

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Maybe I just don't get it but, in my mind, when an object in motion meets a stationary object, there is a lose of momentum thereby slowing down the acceleration process.
Momentum is conserved in a collision, although energy may be dissipated. If you think of each floor as a rigid body, the force of impact acts to speed up the lower floor and slow down in upper floor, such the mu1Vu1 = ml1Vl2+mu2Vu2. The upper floor will have to slow down a little bit momentarily becasue it is subject to the reaction of the force needed to break the support connections for the lower floor.

Christopher Wright P.E. |"They couldn't hit an elephant at
chrisw(--nospam--at)   | this distance" (last words of Gen.
.......................................| John Sedgwick, Spotsylvania 1864)

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