Popular Mechanics responds to Rosie the Ranter, page 13

Also the rate of speed seems to accelerate rather than slow down, as it should have.

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2.

Source

(note NIST says 9 seconds for building 2, faster than free fall in a vacuum)

Basic physics 101...

An object can only fully give up its potential energy, and turn into kinetic energy, in a vacuum with no resistance. So the towers, as they collapsed, should have been experiencing massive resistance from the lower floors that were undamaged. There is no arguing that. So the buildings should not have been able to fully give up their potential energy.
The problem is for the towers and building 7 to have fallen so quickly, all of their potential energy would have to have been lost.

Simple equation, follow along now boys and girls...

(I'm pasting this whole thing because I know a lot of you don't bother looking at links)

The towers were 1350 and 1360 feet tall. So let's start by using our trusty free-fall equation to see how long it should take an object to free-fall from the towers' former height.

Distance = 1/2 x Gravity x Time(squared)

or

2 x Distance = Gravity x Time(squared)

Time(squared) = (2 x Distance) / Gravity

Time(squared) = 2710 / 32 = 84.7

Time = 9.2

So our equation tells us that it will take 9.2 seconds (Ed: Note NIST said 9 secs for WTC2) to free-fall to the ground from the towers' former height.

Using our simpler equation, V = GT, we can see that at 9.2 seconds, in order to reach the ground in 9.2 seconds, the free-falling object's velocity must be about 295 ft/sec, which is just over 200 mph.

But that can only occur in a vacuum.

Since the WTC was at sea level, in Earth's atmosphere, you might be able to imagine how much air resistance that represents. (Think about putting your arm out the window of a car moving half that fast!) Most free-falling objects would reach their terminal velocity long before they reached 200 mph. For example, the commonly-accepted terminal velocity of a free-falling human is around 120 mph. The terminal velocity of a free-falling cat is around 60 mph.
(Source)

Therefore, air resistance alone will make it take longer than 10 seconds for gravity to pull an object to the ground from the towers' former height.

If dropped at the same time, which would reach the ground first?...

And that's just talking about air resistance, remember we also have thousands of tons of steel bolted and welded together in the path of the falling building. You don't think that should have created massive resistance?

C'mon guys, you still think it was jet fuel?

That's a good one, eh?

[edit on 30/6/2007 by ANOK]