1. A Boeing 767 travelling at 590 mph has more energy than a Boeing 757 travelling at 530 mph. (Bigger plane – more mass, higher speed, therefore more kinetic energy). Also walls of reinforced concrete and steel can sustain greater impact than sheets of glass and steel. How did the 757 plowed through more than 235 feet of concrete and steel (Pentagon) and the 767 couldn’t even go through 208 feet of glass and steel (WTC tower 2)?
2. A 1368 foot tall building with 110 floors (approx 12.44 ft per floor) takes 96.9 seconds to collapse under the “pancaking” or “progressive collapse” theory. The WTC towers took close to 10 seconds. 9.25 seconds is the free fall time from the top of the towers. I have explained this in the section below.
3. Gravity on the earth’s surface points downwards. If no other forces are introduced and the resultant is still vertically downwards, why are there plumes and projectiles going sideways and upwards in the videos of the WTC collapse?
The pancaking implies that the top floor collapses on the floor immediately below it and that impact makes the lower floor collapse as well. This implies the second floor from the top can’t start moving till the top floor has reached it after falling through 12.44 feet. The third floor can’t start moving until the 2nd floor reaches it.. and so on. So each floor has to fall 12.44 ft independently before the floor below it collapses. Adding the time taken for this “progressive collapse” you get 96.9 seconds.
enginerd, I see most of the answers you have written are outside the realm of science. I suggest you stick to those fields. No one is claiming perfect knowledge, and the questions I asked are not extremely detailed either. And Occam’s razor (catchy term, huh) has been applied to arrive at these questions. If two projectiles with different energies hit the same material the one with more energy will penetrate further. Occam’s razor right? So obviously the deeper hole was made by something with more energy.
I already explained #2 in detail. The assumptions are extremely unfavorable to me. This model assumes that a floor starts moving as soon as the one above it reaches it. In reality the whole fracturing would take some time and would INCREASE the total time. This model calculates the LEAST time it should take.
#3 really couldn’t be any simpler, right? Might I mention conservation of energy? Or was that an optional topic where you learned your engineering?
Just a side note: I have a degree in rocket science (or aerospace engineering in more mundane terms.) And how long it took for the structure to collapse: 8-12 seconds. Source: Official 9/11 commission report and lots of video footage. Not happy? Ok I’ll assume 15 seconds. Still nearly 6 times as small as 97 seconds. It’s a difference of 5-10 seconds. It’s more than a multiple of 5.
For some people I think I need to see your diplomas before I even start reading your answers. Hehe..