Got a guy on another forum asking this –

This is the maths for the conservation of momentum (known laws of physics) with an inelastic collision.
(m1*v1) + (m2*v2) = (m1 + m2)*v3
Assuming m1 is the falling object ~30 floors and m2 is the stationary object ~80 floors
I shall also give you the benefit of the doubt, that (d) = m/V whereby (d) is a constant.
Assuming 1 floor is approx. 12ft
Please calculate and advise your findings for v3.. when the two structures (m1&m2) collide and then tell me what is wrong with that number
I eagerly await..??

I was never good at this sort of stuff, can someone please help? I know it’s simple but …..

Spiny Norman said:

Got a guy on another forum asking this –

This is the maths for the conservation of momentum (known laws of physics) with an inelastic collision.
(m1*v1) + (m2*v2) = (m1 + m2)*v3
Assuming m1 is the falling object ~30 floors and m2 is the stationary object ~80 floors
I shall also give you the benefit of the doubt, that (d) = m/V whereby (d) is a constant.
Assuming 1 floor is approx. 12ft
Please calculate and advise your findings for v3.. when the two structures (m1&m2) collide and then tell me what is wrong with that number
I eagerly await..??

I was never good at this sort of stuff, can someone please help? I know it’s simple but …..

I don’t quite understand what he means. The stationary object is at 80 floors, and the falling object is at 30 floors. How are they every going to collide?

“I shall also give you the benefit of the doubt, that (d) = m/V whereby (d) is a constant.”

What does he mean? Why would m/V be constant?

I think you need to ask him to clarify.

Ah I think I got it, but if you feel like bashing something out anyway go for it.

Do we know anything about the properties of the two masses? shape, density, modulus of elasticity, strength… anything that will help define the collision?

Also I don’t really understand the kinematics of the question… are both masses falling when they colloid or is one stationary? what assumptions are we to make about the nature of the terminal velocity??

dv said:

Spiny Norman said:

Got a guy on another forum asking this –

This is the maths for the conservation of momentum (known laws of physics) with an inelastic collision.
(m1*v1) + (m2*v2) = (m1 + m2)*v3
Assuming m1 is the falling object ~30 floors and m2 is the stationary object ~80 floors
I shall also give you the benefit of the doubt, that (d) = m/V whereby (d) is a constant.
Assuming 1 floor is approx. 12ft
Please calculate and advise your findings for v3.. when the two structures (m1&m2) collide and then tell me what is wrong with that number
I eagerly await..??

I was never good at this sort of stuff, can someone please help? I know it’s simple but …..

I don’t quite understand what he means. The stationary object is at 80 floors, and the falling object is at 30 floors. How are they every going to collide?

“I shall also give you the benefit of the doubt, that (d) = m/V whereby (d) is a constant.”

What does he mean? Why would m/V be constant?

I think you need to ask him to clarify.

He’s not making a lot of sense and for some reason that’s my fault.
He’s a 9/11 conspiracy person, that should explain a lot.

The 30 floors and 80 floors thing is the top of the tower collapsing. I reckon the ‘problem’ with the equation is that the 80 stories part comes to zero because V2 is zero. So by using this equation in isolation the top of the tower shouldn’t have moved, thus defying gravity.
Oh, and that he’s an intelligent idiot.

Sorry, Spiny. If I were talking to this guy I would try to force him to explain himself more thoroughly because the question as posed seems like gibberish.

But I wouldn’t be talking to him because he’s a 9/11 nutter.

Good luck!

(runs)

Spiny Norman said:

dv said:

Spiny Norman said:

Got a guy on another forum asking this –

This is the maths for the conservation of momentum (known laws of physics) with an inelastic collision.
(m1*v1) + (m2*v2) = (m1 + m2)*v3
Assuming m1 is the falling object ~30 floors and m2 is the stationary object ~80 floors
I shall also give you the benefit of the doubt, that (d) = m/V whereby (d) is a constant.
Assuming 1 floor is approx. 12ft
Please calculate and advise your findings for v3.. when the two structures (m1&m2) collide and then tell me what is wrong with that number
I eagerly await..??

I was never good at this sort of stuff, can someone please help? I know it’s simple but …..

I don’t quite understand what he means. The stationary object is at 80 floors, and the falling object is at 30 floors. How are they every going to collide?

“I shall also give you the benefit of the doubt, that (d) = m/V whereby (d) is a constant.”

What does he mean? Why would m/V be constant?

I think you need to ask him to clarify.

He’s not making a lot of sense and for some reason that’s my fault.
He’s a 9/11 conspiracy person, that should explain a lot.

The 30 floors and 80 floors thing is the top of the tower collapsing. I reckon the ‘problem’ with the equation is that the 80 stories part comes to zero because V2 is zero. So by using this equation in isolation the top of the tower shouldn’t have moved, thus defying gravity.
Oh, and that he’s an intelligent idiot.

The largest problem with application of this formula in this context is that it assume the masses act as large individual objects, not a large number of smaller objects (as would the case in reality)

Cant you just smack him around the head a bit.

Peak Warming Man said:

Cant you just smack him around the head a bit.

I normally don’t solve problems with violence, but I’m tempted to take your lead this time ….

If he was really interested in how it works, there is a paper by a guy called Bazant that explains it with sufficient simplicity to be comprehensible to someone with a reasonable knowledge of the basics.

The Rev Dodgson said:

If he was really interested in how it works, there is a paper by a guy called Bazant that explains it with sufficient simplicity to be comprehensible to someone with a reasonable knowledge of the basics.

I doubt he is, but thanks I’ll try to find it and pass it on.

http://911research.wtc7.net/disinfo/experts/articles/bazant_jem/bazant_zhou.html

Bam.

Spiny Norman said:

http://911research.wtc7.net/disinfo/experts/articles/bazant_jem/bazant_zhou.html

Bam.

He should like that one; it’s a 911 nutter site with added comments.

An original paper is at:
http://www.civil.northwestern.edu/people/bazant/PDFs/Backup%20of%20Papers/466.pdf

but you sure have to wade through a load of crap to find anything sensible on this subject.

That’s not going to help. That paper clearly says the towers collapsed due to steel heating to very high temperatures. Obviously the cause was nanothermite. You’re barking up a lost battle.

The Rev Dodgson said:

Spiny Norman said:

http://911research.wtc7.net/disinfo/experts/articles/bazant_jem/bazant_zhou.html

Bam.

He should like that one; it’s a 911 nutter site with added comments.

An original paper is at:
http://www.civil.northwestern.edu/people/bazant/PDFs/Backup%20of%20Papers/466.pdf

but you sure have to wade through a load of crap to find anything sensible on this subject.

Dang, thanks for picking that up.

Divine Angel said:

That’s not going to help. That paper clearly says the towers collapsed due to steel heating to very high temperatures. Obviously the cause was nanothermite. You’re barking up a lost battle.

Yeah I know.
But I have a lot of spare time, ya know?

Spiny Norman said:

Divine Angel said:

That’s not going to help. That paper clearly says the towers collapsed due to steel heating to very high temperatures. Obviously the cause was nanothermite. You’re barking up a lost battle.

Yeah I know.
But I have a lot of spare time, ya know?

Pffft. You got race cars. Much more fun than troofers. Remember: 386.

rushes in

Ooh…

rushes out