RE: "But it does appear, as result of Hoffman having done it himself, and with the help of Jerry Russell, that the final result should be considered reasonably correct."
Hoffman is a goof. Try this experiment instead. Spend five bucks on a sack of cement (the stuff without the rocks and sand mixed in), then spend another buck on a bag of marbles. Place the marbles in a circle about two feet wide on a level spot on your driveway. Reach into your bag of cement and scoop out a double hand full of the stuff. Drop your cement into the center of the circle of marbles from about chest height and observe the results.
Your non pyroclastic flow of cement will mix with air on the way down, making a cloud of dust, while the main clump of powder will accelerate at something close to 32 feet per second per second. When it hits the ground it will go splat like a water balloon. The kinetic energy of the falling cement will pick up the marbles and move them away from the point of impact.
You can take out your slip stick when you get done, and try to work out the problem in kilowatts, but if you put garbage in, you get garbage out.
If Hoffman was something other than a goof, he would throw his kilowatts in the dumpster, and start over using the design strength of each floor, and calculate the kinetic energy needed to collapse each one.
The problem isn't what it takes to crush and disperse non structural, low compression strength concrete. The problem is what it takes to crush and disperse 47 massive chrome molly steel columns. |
