9/11 Science Club: Mass Does Not Accelerate as it Accumulates, It Can Only Slow Down

[samhall]

.................
The quote you just copied shows his calculations at under 8 seconds for free fall. ....................

The towers were 1368 ft tall. Simple formula for free fall- t=square root of (2H/a).

a= 32.2feet/sec/sec (aka gravity acceleration on planet earth)
t=time in seconds to ground
H= height of free fall

Free fall time was around 9.24 sec discounting any air drag which would only increase the fall time.

 

[ManFromUncle]

The towers were 1368 ft tall. Simple formula for free fall- t=square root of (2H/a).

a= 32.2feet/sec/sec (aka gravity acceleration on planet earth)
t=time in seconds to ground
H= height of free fall

Free fall time was around 9.24 sec discounting any air drag which would only increase the fall time.

Yes now imagine factoring in that "steel drag." The "domino" effect of 100 stories crushing themselves has to be one of the funniest pieces of cartoon physics of all time. Better than Wile E. Coyote falling off a cliff and making a deep hole in the ground all by himself, instead of being squashed flat like a tomato, because the ground is much harder than Wile E.

 

[ManFromUncle]

Like the Bay Bridge fire which caused a freeway collapse - it's a conspiracy!!!!

Yes a bridge is exactly like a tower. Think of them as the same thing.

 

[Trogdor the Burninator]

Yes a bridge is exactly like a tower. Think of them as the same thing.

And steel structures never ever collapse due to heat from a fire - except when they do

 

[samhall]

The towers were 1368 ft tall. Simple formula for free fall- t=square root of (2H/a).

a= 32.2feet/sec/sec (aka gravity acceleration on planet earth)
t=time in seconds to ground
H= height of free fall

Free fall time was around 9.24 sec discounting any air drag which would only increase the fall time

 

[samhall]

And steel structures never ever collapse due to heat from a fire - except when they do

which never happens with steel skyscrapers without a bit of help from a good demolitions expert.

 

[TheQuietRiot]

which never happens with steel skyscrapers without a bit of help from a good demolitions expert.

Amazing how explosives were planted right where the plane impacts and then detonated some time after crash to bring the building down. You can clearly see that both towers collapse downwards from the point of impact. In a controlled demolition the idea is to take out every structural support in the building at the same time, so the entire building collapses together.

But at the end of the day, neither you or I are demolitions experts or structural engineers. The Architects & Engineers for 9/11 Truth movement has roughly 1,750 members, which is a very small minority of that professional industry which has rejected the position that it was a controlled demolitions.

So while it is true that some experts think it was a controlled demolition, the overwhelming majority (not just in the US either) have rejected that position and favor high speed impacts and subsequent fires as the cause of the collapse.

 

[Trogdor the Burninator]

But at the end of the day, neither you or I are demolitions experts or structural engineers. The Architects & Engineers for 9/11 Truth movement has roughly 1,750 members, which is a very small minority of that professional industry which has rejected the position that it was a controlled demolitions.

So while it is true that some experts think it was a controlled demolition, the overwhelming majority (not just in the US either) have rejected that position and favor high speed impacts and subsequent fires as the cause of the collapse.

Let's also remember that Architects & Engineers for 9/11 Truth may as well be called Landscape Architects and Sales Engineers for 9/11 Truth, since any type of architect or engineer is considered "certified" by their organisation.

 

[samhall]

............the overwhelming majority ...................

Proof or just an assumption on your part?

BTW, the opinions of those even with the technical qualifications who have not studied the issues and run some numbers are without value. I myself with 30+ years as an engineer took the Official Version at face value until after two years of relentless in the face challenge by a good friend who is a natural skeptic ran some numbers. Result- when examined the Official Version turns out to be an absurd tissue of lies.

 

[contango]

F = m (dv/dt) + (dm/dt) v.

If mass doesn't change then dm/dv = 0, hence f = m (dv/dt) or f = ma.

...

Here's where you're wrong though. The avalanche (or the 9/11 tower in your case) doesn't slow down - it merely increases it's speed at a lower rate of acceleration. Just because it's acceleration decreases doesn't mean it slows down. It speeds up, but not at a uniform acceleration.

It speed doesn't slow down - it's acceleration does.

Yep, the OP looks rather like the physics equivalent of confusing deficit with debt.

Speed is the cumulative total of acceleration, so to speak. So you can reduce acceleration which means the speed continues to rise although the rate of increase is reduced. To cause the speed to reduce the acceleration needs to become negative (i.e. the rate of change of speed is negative). In the same way reducing the deficit means the debt accumulates at a slower rate, and in order to start repaying the debt we need to remove the deficit completely and return a surplus - a negative deficit (i.e. a surplus) means the debt contracts over time. In this context debt and speed are comparable as are deficit and acceleration.

As mass and speed increase so too does kinetic energy which, IIRC, is equal to 1/2 mv^2. So the increasing mass of each successive floor increases the kinetic energy and the accelerating mass (and the mass will accelerate for as long as the pull of gravity exceeds retarding forces such as friction and air resistance) will cause the kinetic energy to increase further.

I must admit I'm finding both sides of the whole 9/11 discussion somewhat unsatisfactory, and find it frustrating when things are thrown up on either side that appear to add nothing but noise.

 

[keith99]

Yep, the OP looks rather like the physics equivalent of confusing deficit with debt.

Acceleration is the cumulative total of speed, so to speak. So you can reduce acceleration which means the speed continues to rise although the rate of increase is reduced. To cause the speed to reduce the acceleration needs to become negative (i.e. the rate of change of speed is negative). In the same way reducing the deficit means the debt accumulates at a slower rate, and in order to start repaying the debt we need to remove the deficit completely and return a surplus - a negative deficit (i.e. a surplus) means the debt contracts over time. In this context debt and speed are comparable as are deficit and acceleration.

As mass and speed increase so too does kinetic energy which, IIRC, is equal to 1/2 mv^2. So the increasing mass of each successive floor increases the kinetic energy and the accelerating mass (and the mass will accelerate for as long as the pull of gravity exceeds retarding forces such as friction and air resistance) will cause the kinetic energy to increase further.

I must admit I'm finding both sides of the whole 9/11 discussion somewhat unsatisfactory, and find it frustrating when things are thrown up on either side that appear to add nothing but noise.

You got that backwards, speed is the cumulative total of acceleration.

 

[contango]

You got that backwards, speed is the cumulative total of acceleration.

Oops. Good spot, I'll fix it.

 

[keith99]

Oops. Good spot, I'll fix it.

When it was drilled into you which is the integral and which the derivitive things like that stand out even 40 years later.

I almost posted a nastyish post, then I realized the rest was right so that was likely just a slip.

It is easy to jump to a negative conclusion regarding a post in this thread as so many show a clear misunderstanding of very basic Physics.

 

[contango]

When it was drilled into you which is the integral and which the derivitive things like that stand out even 40 years later.

I almost posted a nastyish post, then I realized the rest was right so that was likely just a slip.

It is easy to jump to a negative conclusion regarding a post in this thread as so many show a clear misunderstanding of very basic Physics.

Know what you mean. The irony is certainly there, it's like the law that says any post that points out an error in spelling or grammar will itself contain an error in spelling and/or grammar. Irritating to make the mistake but glad it was caught.

 

[BlandOatmeal]

oopshttp://www.youtube.com/watch?feature=player_detailpage&v=Q_OIXfkXEj0&list=PL416F594906551365

 

[BlandOatmeal]

Finally, the inside info on 9/11:

CONSPIRIACY THEORY DEBUNKED