Date: Wed, 15 May 2002 09:19:35 -0400

Author: Nils Sorensen

Subject: Re: Inertia Ball



I did something similar done with toilet paper this morning. Rip
quick and you get what you want. Too slow and the roll just keeps
spooling out more paper.

There are many high speed shots of balls be kicked or hit that show
inertia pretty well. Some great footage of water balloons that are
shot with a bb and you can see the rubber peel away before the water
starts to drop. Very cool but can't find the name right now. Lots of
stuff by Harold Edgerton that can be found in books or on the web.

Hope this helps,


>I've done that in the past with a 1 kg lab weight and cotton kite
>string. Under the weight, on the floor, I placed a small pillow for
>it to land on. First I yanked the lower string, which of course
>broke. After replacing it, I pulled slowly on the lower string and
>the upper string broke. Moving my hand quickly out of the way, I let
>the weight fall to the pillow.
>I've had great luck with repeatability on this demo.
>On Wednesday, May 15, 2002, at 08:12 AM, George M. Caplan wrote:
>>I will be doing a demonstration for alumnae soon.
>>I plan to do an inertia ball demonstration. i.e. I plan to tie
>>two strings to a weight and hang the weight by one of them.
>>If I pull slowly on the bottom one, the upper one
>>breaks. If I pull quickly, the lower one breaks.
>>Do any of you know of any videos (especially high speed videos) of this?
>>Also, can you suggest any related demos?