In article <56bel3pujn0gv0s189u3hdiqch4huv8btj@[EMAIL PROTECTED]
>, Doctor Evil
says...
>
>The question isn't who destroyed the WTCs...the question is who made
>crazy money on investments that day. Remember the investigation
>determined that and it was immediately sealed to protect Bush's
>pals...
really? where was that re****ted??? i mean besides on
idonthaveagirlfriendso9-11wasaninsidejob.com?
most sincerely,
GodBuilt
>On Wed, 5 Dec 2007 03:38:28 -0800 (PST), schoenfeld.one@[EMAIL PROTECTED]
>wrote:
>
>>WTC Towers: The Case For Controlled Demolition
>>By Herman Schoenfeld
>>
>>In this article we show that "top-down" controlled demolition
>>accurately accounts for the collapse times of the World Trade Center
>>towers. A top-down controlled demolition can be simply characterized
>>as a "pancake collapse" of a building missing its sup****t columns.
>>This demolition profile requires that the sup****t columns holding a
>>floor be destroyed just before that floor is collided with by the
>>upper falling m*****. The net effect is a pancake-style collapse at
>>near free fall speed.
>>
>>This model predicts a WTC 1 collapse time of 11.38 seconds, and a WTC
>>2 collapse time of 9.48 seconds. Those times accurately match the
>>seismographic data of those events.1 Refer to equations (1.9) and
>>(1.10) for details.
>>
>>It should be noted that this model differs massively from the "natural
>>pancake collapse" in that the geometrical composition of the structure
>>is not considered (as it is physically destroyed). A natural pancake
>>collapse features a dimini****ng velocity rapidly approaching rest due
>>the resistance offered by the columns and surrounding "steel mesh".
>>
>>DEMOLITION MODEL
>>
>>A top-down controlled demolition of a building is considered as
>>follows
>>
>> 1. An initial block of j floors commences to free fall.
>>
>> 2. The floor below the collapsing block has its sup****t structures
>>disabled just prior the collision with the block.
>>
>> 3. The collapsing block merges with the momentarily levitating floor,
>>increases in mass, decreases in velocity (but preserves momentum), and
>>continues to free fall.
>>
>> 4. If not at ground floor, goto step 2.
>>
>>
>>Let j be the number of floors in the initial set of collapsing floors.
>>Let N be the number of remaining floors to collapse.
>>Let h be the average floor height.
>>Let g be the gravitational field strength at ground-level.
>>Let T be the total collapse time.
>>
>>Using the elementary motion equation
>>
>> distance = (initial velocity) * time + 1/2 * acceleration * time^2
>>
>>We solve for the time taken by the k'th floor to free fall the height
>>of one floor
>>
>> [1.1] t_k=(-u_k+(u_k^2+2gh))/g
>>
>>where u_k is the initial velocity of the k'th collapsing floor.
>>
>>The total collapse time is the sum of the N individual free fall times
>>
>> [1.2] T = sum(k=0)^N (-u_k+(u_k^2+2gh))/g
>>
>>Now the mass of the k'th floor at the point of collapse is the mass of
>>itself (m) plus the mass of all the floors collapsed before it (k-1)m
>>plus the mass on the initial collapsing block jm.
>>
>> [1.3] m_k=m+(k-1)m+jm =(j+k)m
>>
>>If we let u_k denote the initial velocity of the k'th collapsing
>>floor, the final velocity reached by that floor prior to collision
>>with its below floor is
>>
>> [1.4] v_k=SQRT(u_k^2+2gh)
>>
>>
>>which follows from the elementary equation of motion
>>
>>(final velocity)^2 = (initial velocity)^2 + 2 * (acceleration) *
>>(distance)
>>
>>Conservation of momentum demands that the initial momentum of the k'th
>>floor equal the final momemtum of the (k-1)'th floor.
>>
>> [1.5] m_k u_k = m_(k-1) v_(k-1)
>>
>>
>>Substituting (1.3) and (1.4) into (1.5)
>> [1.6] (j + k)m u_k= (j + k - 1)m SQRT(u_(k-1)^2+ 2gh)
>>
>>
>>Solving for the initial velocity u_k
>>
>> [1.7] u_k=(j + k - 1)/(j + k) SQRT(u_(k-1)^2+2gh)
>>
>>
>>Which is a recurrence equation with base value
>>
>> [1.8] u_0=0
>>
>>
>>
>>The WTC towers were 417 meters tall and had 110 floors. Tower 1 began
>>collapsing on the 93rd floor. Making substitutions N=93, j=17 , g=9.8
>>into (1.2) and (1.7) gives
>>
>>
>> [1.9] WTC 1 Collapse Time = sum(k=0)^93 (-u_k+(u_k^2+74.28))/9.8 =
>>11.38 sec
>> where
>> u_k=(16+ k)/(17+ k ) SQRT(u_(k-1)^2+74.28) ;/ u_0=0
>>
>>
>>
>>Tower 2 began collapsing on the 77th floor. Making substitutions N=77,
>>j=33 , g=9.8 into (1.2) and (1.7) gives
>>
>>
>> [1.10] WTC 2 Collapse Time =sum(k=0)^77 (-u_k+(u_k^2+74.28))/9.8 =
>>9.48 sec
>> Where
>> u_k=(32+k)/(33+k) SQRT(u_(k-1)^2+74.28) ;/ u_0=0
>>
>>
>>REFERENCES
>>
>>"Seismic Waves Generated By Aircraft Impacts and Building Collapses at
>>World Trade Center ",
>>http://www.ldeo.columbia.edu/LCSN/Eq/20010911_WTC/WTC_LDEO_KIM.pdf
>>
>>APPENDIX A: HASKELL SIMULATION PROGRAM
>>
>>This function returns the gravitational field strength in SI units.
>>
>>> g :: Double
>>> g = 9.8
>>
>>This function calculates the total time for a top-down demolition.
>>Parameters:
>> _H - the total height of building
>> _N - the number of floors in building
>> _J - the floor number which initiated the top-down cascade (the 0'th
>>floor being the ground floor)
>>
>>
>>> cascadeTime :: Double -> Double -> Double -> Double
>>>cascadeTime _H _N _J = sum [ (- (u k) + sqrt( (u k)^2 + 2*g*h))/g |
k<-[0..n]]
>>> where
>>> j = _N - _J
>>> n = _N - j
>>> h = _H/_N
>>> u 0 = 0
>>>u k = (j + k - 1)/(j + k) * sqrt( (u (k-1))^2 + 2*g*h )
>>
>>
>>Simulates a top-down demolition of WTC 1 in SI units.
>>
>>> wtc1 :: Double
>>> wtc1 = cascadeTime 417 110 93
>>
>>Simulates a top-down demolition of WTC 2 in SI units.
>>
>>> wtc2 :: Double
>>> wtc2 = cascadeTime 417 110 77
>
>
>
>O'ROURKE: I mean, this is lots of fun attacking George Bush, who is an
>idiot and obviously screwed up on this completely
>BEHAR: Thank you!
>MAHER: Oh, thank you!
>
>PJ O'Rourke on Bill Maher show 9/16/2005
--
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