Its called an impulse function. The force is applied over an extremely small period of time. The plane decelerates but not nearly enough to significantly slow it. Instead, the energy is absorbed by the deformation and failure both the plane and the building.
Steel is not an infinitely strong material, it bends and tears and breaks when subjected to forces greater than then strength of the steel as determined by it dimensions, alloy and temper. Consider that formula for kinetic energy: 1/2mv^2
The weight of a 767 is about 395,00 pounds at take-off. The estimated velocity of the planes when they hit the tower was about 500mph. If you do the math, the kinetic energy of the plane hitting the building = 3.706 billion ft lbs force (5,024,650 Kilojoules). That converts to 1,654,464 ton -force. That is over a million and a half tons striking the building. D0 you think 1.6 million tons of force is enough to break steel?
In terms of the the physics of the collapses, yes. I think there may be political components that we do not know about. There is nothing to support a controlled demolition of any of the buildings. Our government is no where nearly competent enough to pull of a false flag operation of this magnitude without it being leaked.
