Date: Tue Dec 23 18:05:19 2008

Author: Urs Lauterburg

Subject: Re: 2-d motion detector setup

Post:

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Chuck,

Yes you are right. I did not know. It was a guy named George de
Mestral who invented Velcro in 1941.

http://en.wikipedia.org/wiki/George_de_Mestral

Regards and best wishes to you and all other Tap-lers.

Merry Christmas and happy New Year

Urs

Urs Lauterburg
Physics demonstrator
Physikalisches Institut
University of Bern
Switzerland


>Velcro strips on the air table pucks works great.
>A strip of 'vel' wrapped around one and a strip of 'cro' around the other.
>
>A glancing collision will give you the 'dumb-bell' rotation that you
>are looking for.
>
>You must be careful to have the two tracks exactly synchronized to
>find the first pair that occurs after contact.
>
>
> (by the way - I seem to remember that it was some clever
>walker over in .ch land that invented the word Velcro and the stuff
>itself.
>
> Clearly, the inventor spoke French.
> I had Velcro closure shoes in the
>mid-fifties - definitely pre-NASA.)
>
>
>
>On Dec 17, 2008, at Dec 17(Wed) 11:21 , Krishna Chowdary wrote:
>
>>
>>Do you have any good ideas for sticking collisions (let's assume we're
>>
>>talking about an air table, but if you are using hover-pucks, I'd like
>>
>>to hear those experiences as well)?
>>
>>
>>Do you have any good ideas for making "dumb-bells" so that we can see
>>
>>conservation of angular momentum as well as linear momentum?

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Chuck,

Yes you are right. I did not know. It was a guy named
George de Mestral who invented Velcro in 1941.

http://en.wikipedia.org/wiki/George_de_Mestral

Regards and best wishes to you and all other Tap-lers.

Merry Christmas and happy New Year

Urs

Urs Lauterburg
Physics demonstrator
Physikalisches Institut
University of Bern
Switzerland


Velcro strips on the air table pucks
works great.
A strip of 'vel' wrapped around one and a
strip of 'cro' around the other.

A glancing collision will give you the
'dumb-bell' rotation that you are looking for.

You must be careful to have the two
tracks exactly synchronized to find the first pair that occurs after
contact.


(by the
way - I seem to remember that it was some clever walker over in .ch
land that invented the word Velcro and the stuff itself.




Clearly, the inventor spoke French.





I
had Velcro closure shoes in the mid-fifties - definitely
pre-NASA.)



On Dec 17, 2008, at Dec 17(Wed) 11:21 ,
Krishna Chowdary wrote:


Do you have any good
ideas for sticking collisions (let's assume we're

talking about an air
table, but if you are using hover-pucks, I'd like

to hear those
experiences as well)?


Do you have any good
ideas for making "dumb-bells" so that we can see

conservation of
angular momentum as well as linear momentum?




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