Re: DATA on collapsing WTC/more

[brian whatcott <inet@INTELLISYS.NET>]

> At 22:32 9/19/01 -0400, Ludwik wrote:
> > > > At no time was it a free
> > > > fall because the acceleration was never larger than 7 m/s^2. In
> > > > other words, the net force down was never as large as m*g.


When I put a little more effort into the model, I see the virtue
of Glenn's initial proposal which is of this general form:
y = 10.3 t   - 10.7 t^2  + (residuals)
 ...of which I interpret the first term as a resistance force
proportional to velocity, representing a part of the work of fracture.
This expression is in agreement with Ludwik's observation.

The residuals are a very clear sinusoid of amplitude 3.9 ft and period
3 seconds, phase lag is pi. I take it that this is an artifact of the
data capture method - a sort of moire'

brian whatcott <inet@intellisys.net>  Altus OK
                Eureka!