K_Emerson ha scritto:
Citazione:

Sertes ha scritto:
Ho una domanda per i nostri due ufficialisti: se i due blocchi superiori sono rilasciati allo stesso istante quale dei due punti tocca terra per primo, quello blu, quello verde, o arrivano pressochè allo stesso momento?



Aiutatevi pure con gli studi NIST.

Grazie in anticipo

Sertes, che domanda stupida. Ovviamente, crolla prima quello a destra. E, come puoi vedere dai filmati delle torri che crollano, in effetti le macerie proseguono più velocemente del fronte del crollo, come impone la fisica.

"the structure below the level of collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation.

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below, which were unable to arrest the moving mass.”

In other words, the momentum (which equals mass times velocity) of the 12 to 28 stories (WTC 1 and WTC 2, respectively) falling on the supporting structure below (which was designed to support only the static weight of the floors above and not any dynamic effects due to the downward momentum) so greatly exceeded the strength capacity of the structure below that it (the structure below) was unable to stop or even to slow the falling mass. The downward momentum felt by each successive lower floor was even larger due to the increasing mass.

From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.