Anonymous #1 4w

There’s 0 reason to believe it’s not lmao

-3

Anonymous OP 4w

Other than, like, everything

9

Anonymous OP 4w

there is no strong evidence to support the claim that it was done by the US but alright

5

Anonymous #3 4w

Look at how other planes that hit tall buildings deal damage. It doesn’t line up with the total collapse of the building the whole thing wouldn’t go down like that

0

Anonymous #4 4w

Anybody who has studied structural engineering knows that it is exactly what would happen.

4

Anonymous #3 4w

Well I haven’t! Could you explain? I can only draw from comparisons

1

Anonymous #4 4w

so what do you think caused the collapse of not the fucking commercial airplanes that hit them🤦🏼‍♂️

1

Anonymous #1 4w

*if

1

Anonymous #4 4w

An in-depth explanation would take a lot of diagrams and stuff, but here’s a simpler explanation: the building is built to what’s called a certain factor of safety. That’s how many times stronger something is than its expected load. Usually that’s going to be 3 or 4. This is for the loads acting on the structure as a whole. The impact had two effects: it destroyed much of the structure in the immediate site, and it weakened the rest. (1/4)

4

Anonymous #3 4w

This means that the same load from the floors above is spread out across fewer supports, and they’re each weaker. The formula for factor of safety is FS=(strength)/(expected load). In this case, the strength is now lower, and the expected load per beam is higher. Basic math shows us that this makes the factor of safety much lower. As soon as it crosses below 1, we have reached our failure state. (2/4)

7

Anonymous #3 4w

After a while of higher load in on each beam, leading to elastic deformation, and higher temperatures the whole time, that state was reached. As soon as you have the weight of ~20 stories of skyscraper falling on the structure below, the impact becomes much greater, as Force=mass*acceleration. Mass stays the same obviously, and acceleration goes from 0 in the static state to 9.81 m/s^2 of gravity. (3/4)

7

Anonymous #3 4w

This WELL exceeds the failure state for the floors below, and with each floor that joins the collapsing mass, the domino effect continues and increases all the way to the ground. (4/4)

5

Anonymous #3 4w

Actually, I should issue a correction. The force from gravity IS 9.81 m/s^2 in the static state, that’s just weight. The increased impact from falling is momentum, P=mass*velocity. Velocity is what increases. It’s the difference between a brick sitting on you, and falling on you. Velocity increases at a rate of 9.81 m/s^2 from rest, beginning at the moment of failure. As each story joins the collapse, mass increases, and so does velocity due to gravity.

6