Many thanks, Clark. I take note of what you’ve said.
To begin with, it seems that for your calculations to come close to being correct, you would have to demonstrate that at the relevant time the live load bearing capacity of the floors you consider was zero, that is to say that each floor could support no more than its own weight + whatever other weight it was already supporting, and, therefore, its reaction to what was falling on it was due to just its own inertial mass (<b>1</b>/11, <b>1</b>/12, etc.).
I have been under the impression that, according to NIST, I think, the live load bearing capacity of a non-service floor was, for a static load, 12 non-service floors, and for a load dropped – 6 non-service floors. These numbers might be wrong, but the live load bearing capacity of all the floors at the time of collapse is most unlikely to have been zero unless some other factors you have not taken into account had been at play.
I will read in due course all the comments you’ve mentioned.
Keep well.