You're splitting hairs...
No. Not at all. YOu failed to grasp the core message.
What I try to explain - but you either completely fail to understand or consciously ignore - is a very fundamental considerastion: That the basic Laws of Conversation in physics - Conversation of Energy, Conversation of Momentum - apply only to a closed system, not to parts of a closed system.
The closed system that you must consider is, in its simplest form, the entire building resting on a planet that can be, for practical purposes, considered as having unlimited mass. While it is true that the building, as it is progressively destroyed, continuously sucks up part of the potential energy and therefore the motion of "The Building" must at all times be at less than gravitational acceleration relative to earth, this is most emphatically NOT true for PARTS of the building, or the system.
This is what we're talking about:
Source: https://www.youtube.com/watch?v=aBYoKEbIIBg
The roofline starts to descend about 10 seconds into the video.
This is AFTER all of the core has already started to descend, right? After a lot of internal destruction has already occurred, right? After the wall has lost most of its lateral support, right? So what we are talking about is merely a
short interval of time occurring
late into the collapse sequence, right?
For the first 100 feet of the fall, the roofline is going at 9.8 m/s^2.
Unproven, and very certainly FALSE.
For a suitably chosen time interval that probably starts a bit AFTER the roofline started to descend, its motion
averaged 9.8 m/s^2 squared, which
equivalent to g, right?
But - is it constant during that interval?
Probably, demonstrably, no. During a sub-part of that interval, acceleration is >g, and for other parts of the interval, therefore, acceleration is <g.
Both results prove the roofline is NOT "in freefall". It proves the roofline experiences both downward forces (the OP video demonstrates one possible mechanism for this) and residual upward forces in addition to gravity.
Right?
This lasts for about two seconds.
If you plot acceleration vs time, there is nothing in that graph that "lasts for about two seconds". Acceleration increases, decreases, increases again, decreases again along an irregular path. It is never straight and horizontal.
The about two second interval is arbitrarily chosen for the conscious purpose of having it average g.
To describe what everyone can plainly see in the video as "Only a SMALL PART of WTC7" feels like gaslighting and feels like you're being overly defensive.
But it isn't. See the fundamental remark at the beginning of this post: You cannot, in a chaotic event like a highrise collapse, take the motion of an arbitrarly chosen point on the object and treat it as representative of the whole object. IT ISN'T.
Like the debunker doth protest too much. Sure it's the north wall, but that's because that's the only wall we can see in the video!
How do you know you't observe the same on the other walls? You make up stuff.
Well, we can see the northwest wall also, and it's falling just the same.
You mean the West wall?
I would love to see your tracking and measuring of the West wall ... roofline, I suppose
There's no reason to think the walls we can't see are doing something radically different.
But there is every reason to think the CORE is doing something "radically" different. (Like running into the ground).
Anyway, it is pretty unimportant what the other walls do:
The walls are only a part of the structure, and the OP experiment demonstrates how a part of a structure can fall at >g even (and especially!) as it runs into resistance from below.
You cannot deny that, because you have seen the video.