A piece of straw straight on is relatively sharp and pointed. Straw also has long chain sugars (fiber) along it's length which give it substantial strength in that direction. That is why it is so difficult to break straw by just pulling on each end (longitudinal load), but it's easy to tear it (sheering force). In other words, all of it's strength is along the direction of it's length (think of it like a one dimensional object).
The reason you don't find many pieces of straw sticking out of trees is because the straw needs to be headed in exactly the right direction with enough force to penetrate the wood. At all other angles, or slightly less force and the force per unit area is too small to do anything at all to the tree.
In all cases of collision the "winner" is a function of material strength and force per unit area (shape of the object). It has nothing to do with the speed of one object over the other, except in that the overall speed difference changes the "force" part of the equation. From the planes perspective, the building was flying at it at 500 mph.
Steel is unquestionably stronger than aluminum per unit thickness. The shell of an airplane is also substantially thinner than the steel on a building, thus in material strength the building has a substantial advantage. There was either a force per unit area advantage to the plane's wing or there wasn't (think the "sharpness" of the wing). I don't know. I think probably not because wings are actually kinda thick, relatively speaking. Running it through a physics program (FEM) would likely give a reasonable answer. However, your argument of "speed" was not a factor, because the speed of the plane was identical to the speed of the building from each other's perspective.
Don't forget the weight of the jet fuel most of the wing is a fuel tank and they just took off so add a rough guess of 30,000 lbs for each side to the equation. And don't forget the main part of the wing is a fuel tank, its very heavy built. Don't forget the forward and aft terminal fitting and main landing gear trunions those are very heavy parts....
All of the things you are stating are adding onto the force part of the equation. I stated explicitly that that is a factor (Force/area means "force is a part of the equation"). Why are you suggesting that is important? I mean, it is important because it's a part of the equation, but it's not a surprising part of it.
As I said, running it through a simulator would give a reasonable approximation, I wasn't protesting that the airplane would have a force behind it. Indeed, I stated explicitly that it would. I even suggested that it might be enough if the force per unit area was sufficient when compared to the material strength differences, though the building would have a force per unit area as well. The winner is the one with the most force per unit area IF AND ONLY IF it can overcome the relative material strength.
What I was protesting in your response was that "straw going into a tree" was some sort of meaningful evidence. It's not. Well, it is, in that it shows what needs to be considered (force per area and material strength), but it's not in that an analysis of that event shows how unlikely it is (exactly the right angle, along the strength of the object, with the smallest point forward, etc.).
A piece of straw straight on is relatively sharp and pointed. Straw also has long chain sugars (fiber) along it's length which give it substantial strength in that direction. That is why it is so difficult to break straw by just pulling on each end (longitudinal load), but it's easy to tear it (sheering force). In other words, all of it's strength is along the direction of it's length (think of it like a one dimensional object).
The reason you don't find many pieces of straw sticking out of trees is because the straw needs to be headed in exactly the right direction with enough force to penetrate the wood. At all other angles, or slightly less force and the force per unit area is too small to do anything at all to the tree.
In all cases of collision the "winner" is a function of material strength and force per unit area (shape of the object). It has nothing to do with the speed of one object over the other, except in that the overall speed difference changes the "force" part of the equation. From the planes perspective, the building was flying at it at 500 mph.
Steel is unquestionably stronger than aluminum per unit thickness. The shell of an airplane is also substantially thinner than the steel on a building, thus in material strength the building has a substantial advantage. There was either a force per unit area advantage to the plane's wing or there wasn't (think the "sharpness" of the wing). I don't know. I think probably not because wings are actually kinda thick, relatively speaking. Running it through a physics program (FEM) would likely give a reasonable answer. However, your argument of "speed" was not a factor, because the speed of the plane was identical to the speed of the building from each other's perspective.
Don't forget the weight of the jet fuel most of the wing is a fuel tank and they just took off so add a rough guess of 30,000 lbs for each side to the equation. And don't forget the main part of the wing is a fuel tank, its very heavy built. Don't forget the forward and aft terminal fitting and main landing gear trunions those are very heavy parts....
All of the things you are stating are adding onto the force part of the equation. I stated explicitly that that is a factor (Force/area means "force is a part of the equation"). Why are you suggesting that is important? I mean, it is important because it's a part of the equation, but it's not a surprising part of it.
As I said, running it through a simulator would give a reasonable approximation, I wasn't protesting that the airplane would have a force behind it. Indeed, I stated explicitly that it would. I even suggested that it might be enough if the force per unit area was sufficient when compared to the material strength differences, though the building would have a force per unit area as well. The winner is the one with the most force per unit area IF AND ONLY IF it can overcome the relative material strength.
What I was protesting in your response was that "straw going into a tree" was some sort of meaningful evidence. It's not. Well, it is, in that it shows what needs to be considered (force per area and material strength), but it's not in that an analysis of that event shows how unlikely it is (exactly the right angle, along the strength of the object, with the smallest point forward, etc.).
Also don't forget steel is stronger but that aluminum was 7075 t-6 it's much close to steel than pure aluminum.