Date: Fri, 26 Sep 2003 09:11:26 -0500

Author: "Matt Lowry"

Subject: Re: Awesome EM induction demo!

Post:

Tappers,

My copper plate is 10" diam and 1" thick. When we were initially
playing with this, we decided to try a piece of sheet copper about 1/16"
thick. You could feel the braking forces, but just barely. Now I don't
know if this is due to the thickness of the copper or the fact that my
big plate is alloy 101 O2-free Cu. There is no doubt that it is MUCH
more noticable with the big plate.

But one thing that IS interesting is that when you try this out with
copper mesh (as opposed to a piece of sheet copper), you can feel no
braking forces at all! Pretty groovy...

BTW, thanks for all the quick feedback. I don't know how I've lived
without TAP-L!

Cheers,

Matt Lowry
Lake Forest HS
Lake Forest, IL


>>> tbauer@wellesley.edu 9/26/2003 8:33:01 AM >>>
tap-l@listproc.appstate.edu writes:
>Sammy, Zig, Matt, and Tappers all,
>
>I also did this experiment when I was giving a colloquium presentation
to
>my department last monday. I had actually obtained a 1 inch thick by
1
>foot square piece of copper and cooled it for the first time for that
>talk. Dropped the magnet from a height of better than two feet. It
fell
>to 3 inches above the plate and then bounced back up to 6 inches and
then
>slowly dropped back to the plate while sliding sideways. Surprised
the
>hell out of me, and I was prepared for it to bounce.
>Kudos to Doug Osheroff for initiating the revival of this "lost"
demo.
>
>Dale Stille
>U of Iowa
>

Does the copper really need to be this thick? The induction current is
not
very deep, so in theory a piece of 1/16" or thinner sheet should work
just
fine, except for staying cold. I was thinking of using a 1/4" x 12"
sq.
piece for weight and $ considerations.

Tom Bauer
Wellesley College
From KBouff@aol.com Fri Sep 26 07:26:55 2003
From: KBouff@aol.com
Message-ID: <109.27b41aed.2ca5a2c4@aol.com>
Date: Fri, 26 Sep 2003 10:10:12 EDT
Subject: Re: AAPT Photos?
To: tap-l@listproc.appstate.edu
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With regard to pictures, I have asked Doyle often to send me some picturesw
that I can send to the Announcer to brighten up our Section News.
Karen

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AMILY=3D"SANSSERIF" SIZE=3D"2">With regard to pictures, I have asked Doyle o=
ften to send me some picturesw that I can send to the
#000000" FACE=3D"Geneva" FAMILY=3D"SANSSERIF" SIZE=3D"2">Announcer ONT>=
to brighten up our Section News.

               &=
nbsp;         Karen
#000000" FACE=3D"Geneva" FAMILY=3D"SANSSERIF" SIZE=3D"2">

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From peacock@physics.utah.edu Fri Sep 26 07:37:05 2003
Message-ID: <3F744C09.FAF3430D@physics.utah.edu>
Date: Fri, 26 Sep 2003 08:24:09 -0600
From: "Zigmund J. Peacock"
Organization: University of Utah , Department of Physics
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Subject: Re: Van de Graaff
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Judy, I have been using the Winsco belts on my Am.Estat. machine with
success for the last few years. The belt S-W is selling is probably for
the little baby VDG's.
I am in the process of buying a new Science First Van De Graf, the
one with the 14 inch globe, big sparks, etc.
I wouldn't mind building a copy of Sammy's Mother of all Van de
Graf's.
Zig

Judith Elwell wrote:

> I'm glad to see a message about a belt for a Van de Graaff. Please
> comment if someone knows where to get a replacement belt for a Van de
> Graaff made by American Electrostatic Company. I have an order in for
> one to Sargent-Welch, but the size isn't quite the same as the old one
> I have.

Zigmund J. Peacock
WWW.physics.utah.edu/people/staff/peacock.html
University of Utah/Physics peacock@physics.utah.edu
115 SOUTH 1400 EAST #201 Tel 801 581 6602
SALT LAKE CITY UT 84112-0830 Fax 801 581 4801

"We sleep safely in our beds because rough men stand ready in
the night to do violence to those who would do us harm"
-- George Orwell

"All that is necessary for the triumph of evil is that good
men do nothing!"
-- Edmund Burke


--------------B40BD7416B46A2F2B540CD7E
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Judy, I have been using the Winsco belts on my Am.Estat. machine with success
for the last few years. The belt S-W is selling is probably for the little
baby VDG's.

    I am in the process of buying a new Science First
Van De Graf, the one with the 14 inch globe, big sparks, etc.

    I wouldn't mind building a copy of Sammy's Mother
of all Van de Graf's.

     Zig

Judith Elwell wrote:


I'm
glad to see a message about a belt for a Van de Graaff.  Please comment
if someone knows where to get a replacement belt for a Van de Graaff made
by American Electrostatic Company.  I have an order in for one to
Sargent-Welch, but the size isn't quite the same as the old one I have.

Zigmund J. Peacock          
WWW.physics.utah.edu/people/staff/peacock.html

University of Utah/Physics                  
peacock@physics.utah.edu

115 SOUTH 1400 EAST #201                    
Tel 801 581 6602

SALT LAKE CITY UT 84112-0830                
Fax 801 581 4801

 "We sleep safely in our beds because rough men stand ready in

the night to do violence to those who would do us harm"

        -- George Orwell

 "All that is necessary for the triumph of evil is that good

men do nothing!"

         -- Edmund Burke

 

--------------B40BD7416B46A2F2B540CD7E--
From britton@ncssm.edu Fri Sep 26 07:41:02 2003
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