Re: DATA on collapsing WTC/more

[Bernard Cleyet <anngeorg@PACBELL.NET>]

I haven't been following this thread, but did it appear that the
acceleration was "bumpy" due to the resistance from  the closed (lower)
part of the accordion's meeting each successive intact floor?

bc



brian whatcott wrote:

> > 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!