I'm an electronics engineer.
How long?
You're an engineer who confuses speed & acceleration?
When it comes to "the structural engineering of massively large structures that are in the process of collapse", you are an amateur. And, from reading your replies here, an incompetent amateur.
(Sorry. If you've been in the field >10 years, you'll understand my bluntness.)
I've got 37 years of continuous, successful experience as a mechanical engineer.
That allows me to follow the mechanical & structural engineering arguments in fine detail.
However, while not an amateur, I am NOT an expert.
The specific expertise that I bring to this discussion is 37 years of engineering epistemology.
Whose 1st rule is: Ignore amateurs. Listen very, very carefully to experts.
2nd rule: expertise is VERY narrowly defined.
Experts, in this case, are ONLY structural engineers who specialize in the failure modes & failure analysis of extremely large structures, and have done so successfully for >25 years.
Zdenek Bazant is an expert. This has been exactly his field for about 50 years.
I think it does, as it gives us an initial model to work with. We can refine things from there on.
…
I'd put it in the CENTER of the block. The center of gravity. But that's just me.
And you'd be simply, completely, utterly wrong on both counts.
So put the brick at the BOTTOM of the upper block and do the math again. How much does that cut? A second? Total drop type in vacuum 8.2 and 10.9 with drag? So that's a 5 second difference cutting through air vs cutting through the whole building.
I heard you. That's what I'm saying. That resistance is huge and surely would slow down the top a whole lot more than 5 seconds if air alone would slow it 3.
You are talking about "resistance". More specifically, a resistive force.
What are the units of force?
Are they "seconds"?
Your pulling "seconds" out of your butt, and handwaving your imagined correlation between seconds & force simply demonstrates that you're an amateur at the mechanics of the collapse.
Sorry to be harsh.
But it is all the simple truth.
tom