[Phys-l] Fun Slinky Demos (was: general science surveys anyone?)

["Krishna Chowdary" <chowdark@evergreen.edu>]

2008/6/4 Savinainen Antti <antti.savinainen@kuopio.fi>:
> "My comment about physicsts getting it wrong relates to an interactive demonstration that I do with a
> slinky."
>
> Could you give more details on the demonstration? It might be a good opportunity to learn!

I'm not David Marx, but one of my favorite demos with a slinky goes
something like this (I did not invent either the demo or the
interactive part, but I've seen it in multiple places in real life and
on video):

Allow a slinky to extend vertically, holding it at the top but free at
the bottom.  Damp out its motion so it is essentially motionless.

Ask your audience to predict the motion of the top of the slinky and
the bottom of the slinky upon release of the top end.

Sometimes I've seen multiple choice options (will the top and bottom
fall at the same rate? will the top remain stationary while the bottom
rises?  will the top fall and the bottom rise until they meet in the
middle?  will the bottom remain stationary while the top falls, etc).

-Krishna