Originally Posted by mhgaffney
1. Energy can only be expended once. If you look at the collapse videos -- one can clearly see that the top floors disintegrate before our eyes. They turn to dust in mid air.
This disintegration expends the potential energy contained in the top floors. Once it is expended -- that energy is no longer available to exert a crushing effect on the floors below. This is according to the law of conservation of energy.
Talk about babbling idiocy. Once again you demonstrate that you don't have the first ****ing clue about physics.
If you have m kg of mass @ h m height, you have mgh potential energy, no matter what the form of the mass. That the parts of the building were falling apart in no way "expends their potential energy". The only thing that expends* potential energy is FALLING.
1kg of lead brick @ 1m has *exactly* the same potential energy of 1kg of lead dust @ 1m (or 1kg of feathers for that matter).
* Energy is never "expended" it only is converted to other forms (including mass).
Also, the hammer effect is the result of the top 20 floors of the tower (which certainly did NOT disintegrate before the collapse) smashing into the lower 90 floors. See: