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Re: WTC North Tower collapse data

At 11:29 PM 9/17/01, I wrote:
The Excel best fit 2nd degree polynomial for the adjusted vertical position
v. time after 1 s is

Even better is the best fit power curve for magnitude of displacement from
initial position in feet for t>=1.2757 s (assuming collapse begins at
1.0071 s):

y=16.779 t^1.8124, where t is time since collapse
R^2 = 0.9722

Kinda looks like free fall to me.

Now, there's a lot of scatter in the data in the first second of the
collapse, so it's hard to tell if the building is immediately in free
fall. But if not, after the first few floors gather some momentum, the
lower floors don't put up much of a fight, and the building approaches free
fall pretty quickly.

Glenn


------------
Glenn A. Carlson, P.E.
St. Charles Community College
St. Peters, MO USA
www.stchas.edu/faculty/gcarlson/physics
PGP Fingerprint E88D 2AB8 C5A8 D231 06B9 1597 3C72 5CC2 7D87 5519
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