WTC Collapses

I say LEVELS not Floors because I don't know when people are just talking about the square donut floor slabs and when they mean the entire mass including the core and perimeter columns on each level.

This is what my second video is about. The falling mass must do TWO THINGS. It must break the supports of the stationary mass which requires energy and It must overcome the inertia of that stationary mass. In the first 1/10th of a second gravity only causes a mass starting from zero velocity to travel two inches and move at 3 ft/sec. A mass that has been falling for longer than that is already moving significantly faster so conservation of momentum comes into play. An object that has fallen 4 feet is traveling at 16 ft/sec. The bottom line is that each level slows the TOTAL MASS down and reduces its kinetic energy more than it increases it because kinetic energy is the square of the velocity. Consequently the top of the north tower should have stopped, if it didn't do the far more likely thing of falling off the side.

People need to ignore the right data in order to BELIEVE that straight down gravitational collapse. EXPERTS should have been saying that accurate information about the distribution of steel and concrete was necessary within months of 9/11. It is totally hilarious that the NCSTAR1 report doesn't even specify the total for the concrete.

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R. Mackey is a sophist and helps encourage people to believe what they prefer.

Did you read FALL OF PHYSICS or not? It shows that changing the distribution of mass changes the collapse time of a 64 foot fall even without the strength of the material as a factor.

psik

 

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Floors?, levels?, once the top 15% is in motion the only resistance it is going to meet is the floor just below the falling mass, and that single floor is not enough to support or slow the falling mass, not only that, as that floor collapses it adds it's mass to the 15% adding energy, mass, and motion. so the next floor is hit with 15.5% of the total mass.

Newton’s 1st Law of Motion.

The only action on the mass is the resistance of the floor just below it, and that doesn't have enough resistance to affect the falling mass, in fact it add its mass, and goes in to motion, adding energy and mass to the event.

 

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why will (1/17)* M not slow M in a collision?

M = mass of 17 floors (15% of 110 floors)

 

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It may for the first resistance floor, and even the second and a few floors beyond that, but you still have Mass in motion.

I may be using the wrong term but ballistic coefficient, the mass of the top 17 floors has a ballistic coefficient, and the mass and coefficient for the top 15% is greater then the resistance of the single floor below it, and as that floor adds it mass, the coefficient, mass, and energy, grow.

 

conservation of momentum

(m1*v1) + (m2*v2) = (m1 + m2) * v3

d = height between 2 floors = 417/110 = 3.8 meters
v3 = speed of combined mass
(m1*v1) = M * 8.63
(m2*v2) = 1/17 M * zero
speed at which M hits M/17 assuming freefall = g*(squareroot(2(d/g))) = 8.63 m/s

(M * 8.63) + 0 = (M + M/17) * v3

v3 = 8.63M / 1.059M

v3 = 8.15 m/s

before collision, speed = 8.63 m/s
after collision, speed = 8.15 m/s

 

But what is the collision speed after the new mass and momentum is added to the existing mass? and what about the directional coefficient?

The directional coefficient would grow as mass is added, just as in a bullet, the longer and heaver the bullet the better it resist the force's of drag, and resistance.

But you also have a force working on the moving mass, gravity, and doesn't gravity add to acceleration if the mass is increased?

Newton's First Law
"Every body continues in a state of rest or in a uniform motion in a straight line, until it is compelled by a force to change its state of rest or motion."

Newton's Second Law
"Change of motion is proportional to the force applied, and take place along the straight line the force acts."


And as floors are added to the mass there is a shifting of mass and energy, to the mass above the resistance floor, so eventually you have 50%+ and adding mass, to the down ward motion.

Also would there be enough of a slow down to stop the collapse before bottoming out?

 

the speed of the mass after impact is right there at the end of the calculation - 8.15 m/s

the impact of the top 17 floors into a single floor will slow the speed from 8.63 m/s to 8.15 m/s (or in mph, from 19.3mph to 18.2mph)

this even assumes zero resistance from the single floor and zero column support and connections between floor and impacting mass.

 

You still are ignoring Newton's Laws, and gravity as a force in your equations.

g = 9.8 m/s/s, downward
( ~ 10 m/s/s, downward)

Plus the fact that you seem to be treating each floor as a separate event, instead of a chain of events in which there is a constant changing of variables, mass, energy, momentum, and I would suppose velocity and gravity acceleration.

 

we are dealing here with two instantaneous events occuring immediately after each other. In the quantum of time just before the upper block impacts the single floor is the first event. the second event is the quantum of time just after the impact. therefore g has no bearing between these 2 quantums of time, effectively the time is zero, thus the speed does not change according to g. the impacted mass will then accelerate over a period of time until it hits the next "floor"

your original statement "that single floor is not enough to...slow the falling mass" is false according to the conservation of momentum.

perhaps you could explain how newtons laws have a bearing in what i have said here, simply saying i have ignored something is no more helpful than stating "you are wrong" and then failing to give an explanation as to why.

 

My knowledge of physics isn't the best, but I believe I understand the argument. In space, where there is no gravity, when a moving object hits a stationary one, the moving object is still slowed due to the mass of the still object. And we're not even taking into account the fact that in a building, the lower floors would put up some resistance not just fall down like a house of cards.

 

right, the moving object has to transfer some of its (kinetic) energy to the stationary object in order to get it to move. some of that (kinetic) energy from the moving object will also go into breaking the stationary object (columns buckling, bolts snapping, concrete crushing, sound waves, friction etc).

actually, no it doesn't, if you recall the experiment armstrong did on the moon dropping a hammer and a feather at the same time, both hit the floor at the same time, so the quantity of mass has no bearing on acceleration due to gravity. you might be thinking of air resistance which is negligible enough to be ignored when dealing with a building collapse.

 

But again you forget the accumulating mass, and no they are not separate events, they are a accumulating event.

Motion, once something is in motion it tend to stay in motion unless acted on by another force, but the force of resistance of the next floor is affected by the force of gravity acceleration of the falling mass.

Gravity acceleration is the same for everything, and once the resistance of the lower story is overcome, the mass returns to the speed of gravity acceleration, and impact the next floor at speed plus the additional mass of the now destroyed floor.

This is not taking place in a vacuum, in space with a vacuum I would think that you would be correct, but we have gravity as a active force in the process, and your equation fails to account for the effect of Gravity and Gravity Acceleration to the falling mass.

Through gravity there is a constant force on the moving mass, were in the floors the resistance is a temporary factor, that is over come by the constant force of Gravity/ Gravity Acceleration.

 

In a vacuum, yes, but now do the same experment on earth, and guess which one will accelerate faster, you are not accounting for the difference in resistance, between vacuum and atmosphere.

Vacuum no resistance, atmosphere lots of resistance.

 

I said "you might be thinking of air resistance which is negligible enough to be ignored when dealing with a building collapse."

stop trolling!

 

Your numbers still differ from those of Biederman.

From
http://www.me.wpi.edu/MTE/People/Images/IMSBiedermanA2.pdf

The as-fabricated microstructure consisted of a hot worked banded structure of ferrite and pearlite.
In severely “eroded” regions where the thickness had been reduced to less than a 1/16 of and inch
significant decarburation was observed. In addition, some pearlite bands presented regions that had
re-austentized as well as regions where the pearlite had started to spheroidize. These observations
indicate that steel had experienced temperature between 550 and 850°C.
An examination of the “slag” that formed on the surface of the steel found iron oxides and iron
sulfides. It appeared that the “slag” was liquid at high temperature and easily attacked the grain
boundaries. A eutectic microstructure was seen within the “slag” of iron oxides and iron sulfides. If
these compounds were pure Wustite (FeO) and Iron sulfide (FeS), the eutectic temperature is 940°C.
It appears that the severe “erosion” was due to the sulfidation and oxidation (i.e. hot corrosion) of
the steel followed by the liquid “slag” attack of the grain boundaries.

Chemistry is not my thing so I have to go to R.Mackey again.

"
Regarding the melting/boiling temperature of other sulfur compounds, you forget that the sulfur may have started to react with the steel before it was heated, or the two could have been concurrent. To pick an obvious example, sulfuric acid from overheated uninterruptible power supplies could have flowed onto structural steel at a temperature of about 100oC, then started to react with the steel, and then was further heated eventually to a temperature of about 900oC. The sulfur would bond to iron and form more heat-resistant compounds (but far less heat resistant compounds than steel itself) first. There is no reason at all to assume the sulfur started at the upper temperature.
....
The sulfur that caused the eutectic probably started as an acidic form, such as H2S or a weak solution of H2SO4 (sulfuric acid). "

 

Not trolling, just pointing out that there is a difference in actions in atmosphere and in vacuum, the gravity effect is the same but the air resistance is massively different, your postulation that the air pressure resistance was negligible in atmosphere support my supposition, and your citation of Armstrong's demonstration on the moon has no bearing on the events here, a experiment in vacuum is not applicable to actions in atmosphere, different factors, vacuum/atmosphere.

Gravity and Gravity Acceleration, of Mass, constant, the resistance of the single floor, is not, it is over come, and then Gravity and Gravity Acceleration, of Mass, resumes, till the next event, but now we have more mass to overcome resistance.

 

No it isn’t.

Temperatures of 1000C are quite possible in an office fire.

What I see a lot of from the truthers though is testing one possibility, finding that wouldn’t answer the question so the answer must be thermite.

When you were talking about molten metal you were not referring to eroded steel which had undergone sulfidation at temperatures near 1000C though. You were referring to large amounts of molten steel which was a result of very high temperatures.

 

See post 809 for an indication.

They did not require every piece of the 200,000 tons of steel just to determine what happened.

 

Zbigniew Brzezinski brought in Samuel Huntingdon (author of The Clash of Civilizations and the Remaking of World Order ) into the white house in 1979 who drafted memorandum 32 creating FEMA. In Huntingdons book The Crisis of Democracy: Report on the Governability of Democracies to the Trilateral Commission "A government which lacks authority will have little ability, short of a cataclysmic crises, to impose on its people the sacrifices which may be necessary to deal with foreign policy problems and defence....we have come to recognise there are potential limits economic growth. There are also potentially desirable limits to the indefinite extension of political democracy" - page 69, The Road to 911 Peter Dale Scott.

Disaster at home = desirable fascism + new world order + offensive wars abroad = neocon agenda.