uruk
Philosopher
- Joined
- Apr 9, 2003
- Messages
- 5,311
It can deaccelerate the impactor but that energy had gone into the impacted mass The energy has gone into disarticulating the structures of the impacted floor. Remember that gravity is still applying a force. If the impacted structures are damaged so that they can no longer support the load of the upper impacting mass the movement of the upper mass will continue into the the next floor applying the force of momentum plus the added mass of the floor that was disarticulated.No, it will not happen! Reason is that F2 is of very short duration and, applied to the impactor, decelerates the impactor, etc, etc, and arrests it. Plenty of energy absorbed in the process which is very quick.
Why not? the columns are still being impacted.Note that F2 is not applied to any columns! It is applied to floors, that fail, etc, etc. and consume energy. F2 acts as a brake.
Remember when the floor fail they can no longer provide structural support or bear loads. The structure were designed to support a static mass not mass plus kenetic energy. Remeber Newton. Energy is not consumed just changed to another state.
The upper structur is not indestructable but the mass still remains and is still in motion impacting on the floor below it.Note that Bazant 'assumes' that the upper block is rigid, i.e. it cannot fail; it is indestructible, friction has no effect on it, even if F2 should be able to decelerate it, which Bazant conveniently ignores.
The mass still remains if the structures rigidity does not.Therefore, logically, any F2 acting on Bazant's rigid upper block cannot stop it, which then Bazant via some magic equations tries to prove. But no such upper, rigid block exists in reality! As soon as Bazant assumes that the upper block is not rigid, he will get the same result as I have presented in my papers.
The individual pellets from a shot gun blast still imparets energy on a target dispite the fact that they are not rigidly connected to each other. The energy is accumulative.