Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: 9-11 Wackos

[Subject Prev][Subject Next][Thread Prev][Thread Next]

And remember, the resistance strength at each floor is constant. So as you go down the building, each floor has the same capacity to resist the pancacking, but the force cannot be overcome due to the ever increasing mass and acceleration to the point that it becomes neglible to momentarily slow down the fall.


On 5/25/07, Christopher Wright <chrisw(--nospam--at)> wrote:

> 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

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

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at:
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*   Questions to seaint-ad(--nospam--at) . Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at:
******* ****** ****** ****** ******* ****** ****** ********