Creative Speculation
In reply to the discussion: North Tower Acceleration [View all]jesters
(108 posts)"...The force after the upper block's mass fell a dozen feet between the floors is far greater than the resisting force of the intact section of the lower block."
First of all, the upper portion was never in free fall. (In fact, haven't 9/11 "debunkers" spent ten years arguing this very point??) So that is a deliberate miscalculation right off the bat. Secondly, and this apparently needs to be repeated across the internet: For the upper portion to EXERT THAT FORCE would REQUIRE IT TO DECELERATE. IF IT'S NOT DECELERATING, IT'S NOT EXERTING A FORCE. Because there's nothing to exert it against.
"So it must accelerate all the way down, especially after the debris between the blocks increases during the collapse which provides more mass to accelerate the collapse."
You're just repeating Bazant's cartoon model which has largely been discarded by both sides of the debate now. No, it would not accelerate all the way down. There's no model that has been put forward anywhere that can explain a debris-driven, top-down destruction (and pulverization) of an intact steel-framed skyscraper. If you know otherwise, please refer us to it.