Child,
Not sure if tfk's post is worth replying to. He merely regurgitates Bazantian fantasy physics.
Bazant:
Education
C.E., Czech Technical University, Prague, Civil Engineering (Structural Engineering) 1960
Ph.D. (in mechanics)., Czechoslovak Academy of Sciences, Prague 1963
Postgraduate diploma in Physics, Charles University, Prague 1966
Docent habil., Czech Technical University, Prague 1967
S.E. 1970, Illinois Registered Structural Engineer
Teaching Activities
Inelastic Analysis of Structures
Stability of Structures
Cohesive Fracture and Scaling
Honors and Awards
Elected to: National Academy of Sciences;
National Academy of Engineering;
American Academy of Arts and Sciences;
Austrian Academy of Sciences;
Accademia Nazionale dei Lincei (Rome);
Spanish Royal Academy of Engrg.;
Engrg. Academy of Czech Rep.;
Academia di Scienze e Lettere (Milan);
European Academy of Sciences and Arts.
Six Honorary Doctorates (Boulder, Prague, Karlsruhe, Milan, Lyon, Vienna).
Awards & Prizes
Prager Medal from Society of Engineering Sciences;
von Karman Medal;
Newmark Medal;
Lifetime Achievement Award;
Croes Medal;
Huber Prize and TY Lin Award from ASCE;
Honarary Member ASCE;
Nadai Medal and Warner Medal from ASME;
L'Hermite Medal from RILEM;
Exner Medal, Austria;
Humboldt Prize, Germany;
Torroja Medal, Spain;
Solin Medal, Prague;
Z. Bazant (Sr.) Medal, Prague;
Stodola Medal, Slovakia;
Roy Award, Am.Ceramic Soc.;
ICOSSAR Award;
Czech Soc. for Mech. Medal;
Outstanding Contribution Award, IACMAS;
Guggenheim, NATO, JSPS, Humboldt, Ford and Kajima Fellowships;
National Winner, 1958 Math.Olympics, Czechoslovakia;
Among top 100 Highly Cited Scientist in Engineering ( >9300 citations )
Former President of SES, IA-FRAMCOS (founder) and IA-CONCREEP (founder);
Former Editor, Journal of Engineering Mechanics, ASCE.
Selected Publications
Textbooks (Number: 6)
Books Edited with Chapter Contributions (Number: 20)
State-of-Art Articles and Research Review Articles (Number: 51)
Published Biographies and Volumes Dedicated to Bazant (Number: 12)
Research Articles in Conference Proceedings (Number: 208)
Public Policy Contributions (Number: 5)
Research Articles in Refereed Journals and Book Chapters (Number: 484)
___
Feel free, child, to publish your resume, CV or list of publications.
He seems to be talking about the twin towers here, for reasons unknown. Or for the reason that he had no clue what was being discussed in the first place.
Apparently, you failed to comprehend that the equation that you cited ("F = ma") applies to every interaction of every object in this universe.
Objects which include WTC1, 2 & 7.
In any case, in lay terms, the impact of the upper building portion on the lower building portion will be transferred through much of or the entire lower building portion--on account of the intact structural steel framing.
And yet, F = ma.
And there are various parts that are accelerating, and others that are not.
A car is driving thru a field of corn stalks at a CONSTANT 30 mph.
The front bumper is hitting stalks of corn.
By Newton's 3rd law, the force that the bumper is exerting on the corn is equal & opposite to the force that the corn is exerting on the bumper.
And yet, the corn is accelerating during the collision while the front bumper is NOT.
The net force on the corn is a high value.
The net force on the bumper is zero.
Get it yet?
The forces that the colliding bodies exert on each other have to be equal in magnitude & opposite in direction, but there is nothing that says that these are the
ONLY forces that can be operating on either body.
What tfk is pretending to "explain" here makes no sense.
Your ignorance does not make the physics a "fantasy".
It's time for you to either attempt to learn some rudimentary concepts or to be hush.