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Originally Posted by chal7ds They likely got false reports of it "about to collapse"?!? LOL!!! Did you not hear or read about the countdown that happened at ground zero that day before WTC 7 came down? Firefighters were told it was going to come down, they had a COUNTDOWN, and then 9/11 1st responders like Craig Bartmer and Kevin McPadden (as well as many others) both came out and said they heard obvious explosions going off as it came down. We also have Silverstein using demolition language like they decided to "Pull It" as well as this building THAT DIDN'T GET HIT BY A PLANE falling in under 6.5 seconds neatly into its own footprint. How is that possible when no other steel structure in history has collapsed that fast and neat in that amount of time? It is physically impossible. I guess Newton's laws don't apply here huh?
Not satisfied? Why did the BBC and CNN also report the collapse too early? YouTube - BBC Reported Building 7 Collapse 20 Minutes Before It Fell YouTube - WTC 7 Foreknowledge
ohhh, but I suppose they just got reports it was 'about to collapse' and reported it too early huh? lol. You gotta be kidding me. Who could have guessed a burning steel building was going to collapse? NO ONE. The only possible answer to that is that someone knew about the building coming down beforehand and started warning the people and the firefighters and rescue workers. Of course, if someone knew, then the official story is worthless.
Anybody who believes that WTC 7 came down as a pancake collapse has to be either a retard or a government operative hired to try and hold up this 'official story' which by each day continues to slowly fall apart.
chal7ds
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Here's my source which says that you are wrong.
Debunking 9/11 Conspiracy Theories and Controlled Demolition - Free Fall
The time required to strip off a floor, according to Frank Greening, is a maximum of about 110 milliseconds = 0.110 seconds. It is rather the conservation of momentum that slowed the collapse together with a small additional time for the destruction of each floor.
Below are calculations from a physics blogger...
When I did the calculations, what I got for a thousand feet was about nine seconds- let's see,
d = 1/2at^2
so
t = (2d/a)^1/2
a is 9.8m/s^2 (acceleration of gravity at Earth's surface, according to Wikipedia), [He gives this reference so you can double check him.]
d is 417m (height of the World Trade Center towers, same source)
so
t = (834m/9.8m/s^2)^1/2 = 9.23s
OK, so how fast was it going? Easy enough,
v = at
v = (9.8m/s^2 x 9.23s) = 90.4m/s
So in the following second, it would have fallen about another hundred meters. That's almost a quarter of the height it already fell. And we haven't even made it to eleven seconds yet; it could have fallen more than twice its height in that additional four seconds. If the top fell freely, in 13.23 seconds it would have fallen about two and one-half times as far as it actually did fall in that time. So the collapse was at much less than free-fall rates.
Let's see:
KE = 1/2mv^2
The mass of the towers was about 450 million kg, according to this. Four sources, he has. I think that's pretty definitive. So now we can take the KE of the top floor, and divide by two- that will be the average of the top and bottom floors. Then we'll compare that to the KE of a floor in the middle, and if they're comparable, then we're good to go- take the KE of the top floor and divide by two and multiply by 110 stories. We'll also assume that the mass is evenly divided among the floors, and that they were loaded to perhaps half of their load rating of 100lbs/sqft. That would be
208ft x 208ft = 43,264sqft
50lbs/sqft * 43264sqft = 2,163,200lbs = 981,211kg
additional weight per floor. So the top floor would be
450,000,000 kg / 110 floors = 4,090,909 kg/floor
so the total mass would be
4,090,909 kg + 981,211 kg = 5,072,120 kg/floor
Now, the velocity at impact we figured above was
90.4m/s
so our
KE = (5,072,120kg x (90.4m/s)^2)/2 = 20,725,088,521J
So, divide by 2 and we get
10,362,544,260J
OK, now let's try a floor halfway up:
t = (2d/a)^1/2 = (417/9.8)^1/2 = 6.52s
v = at = 9.8*6.52 = 63.93m/s
KE = (mv^2)/2 = (5,072,120kg x (63.93m/s)^2)/2 = 10,363,863,011J
Hey, look at that! They're almost equal! That means we can just multiply that 10 billion Joules of energy by 110 floors and get the total, to a very good approximation. Let's see now, that's
110 floors * 10,362,544,260J (see, I'm being conservative, took the lower value)
= 1,139,879,868,600J
OK, now how much is 1.1 trillion joules in tons of TNT-equivalent? Let's see, now, a ton of TNT is 4,184,000,000J. So how many tons of TNT is 1,139,879,868,600J?
1,139,879,868,600J / 4,184,000,000J/t = 272t
Now, that's 272 tons of TNT, more or less; five hundred forty one-thousand-pound blockbuster bombs, more or less. That's over a quarter kiloton. We're talking about as much energy as a small nuclear weapon- and we've only calculated the kinetic energy of the falling building. We haven't added in the burning fuel, or the burning paper and cloth and wood and plastic, or the kinetic energy of impact of the plane (which, by the way, would have substantially turned to heat, and been put into the tower by the plane debris, that's another small nuclear weapon-equivalent) and we've got enough heat to melt the entire whole thing.