Here's an interesting quirk of Physics: if you hold a Slinky spring-toy in mid-air and then drop it, the base of the Slinky becomes momentarily suspended in mid-air, apparently defying gravity:
Physics Student Dan Walsh provides a detailed explanation of this phenomenon, but the basic explanation is that while the center of gravity of the Slinky does indeed accelerate towards the ground at one gee, the base of the slinky is simultaneously accelerated upwards by one gee: the contracting force from the spring itself that, until the moment of release, was counteracting the gravitational force. The net result: the base remains stationary. You can see more in a longer version of the above clip, and a subsequent experiment with an even longer slinky (which exhibits the same behaviour).
Dan's Geometrical Curiosities: Explaining an astonishing slinky
An excellent demonstration of the collapse (the pancaking of each floor)of the World Trade Center towers. (Without the anti-gravity nonsense)
Posted by: Ferd Berfel | October 30, 2011 at 12:29
Simply put, the slinky contracted quicker that it fell. the above explanation must of been made by one of the geniuses that developed the "new" math, that they are polluting the minds of the kids of this country.
Posted by: Jim | October 31, 2011 at 06:53