Good explanation—another way to think of it is that everything but the top of the slinky is exerting a tension on the top of the slinky which is acting in the direction of gravity (at least at the start). Hence the top of the slinky feels more force than just gravity and does accelerate downwards faster than with just gravity.
Thanks for the tip.
The center of mass of the slinky accelerates at normal gravitational acceleration. The bottom of the slinky is stationary, so to compensate the top part goes extra-fast. I did a short calculation on the time for the slinky to collapse here http://arcsecond.wordpress.com/2012/07/30/dropping-a-slinky-calculation-12/
Good explanation—another way to think of it is that everything but the top of the slinky is exerting a tension on the top of the slinky which is acting in the direction of gravity (at least at the start). Hence the top of the slinky feels more force than just gravity and does accelerate downwards faster than with just gravity.