Date: Fri, 4 Oct 2002 12:29:31 -0400 (EDT)

Author: Richard Berg

Subject: Re: Wilberforce Pendulum?

Post:

Jason,

I think that almost all springs would do it - you just have to find the
right geometry for the weight and arms. The one on our web site uses the
standard Cenco(?) tapered spring. I have one on my desk about a foot long
with a rather light bob. The one that we used for a paper on the subject
AJP 59(1), 32-38, Jan (1991) is a very light very long spring from
Leybold. In fact, many of our standard "mass on spring" demos have a
tendency to start into rotational motion, but don't do very well because
they have not been tuned up appropriately.

Dick Berg

On Fri, 4 Oct 2002, Jason St. John wrote:

> Seems like in general, it won't be that easy. Your spring has to have
> large appreciable overlap of the linear regions in both the longitudinal
> and torsional restoring forces, whereas most springs don't.
>
>
> --
> Jason St. John
> Boston University
> Curator, Physics Demonstrations Collection
> 617.353.2634
> stjohn@bu.edu
>
> On 2002-10-04.11:43 owner-tap-l@listproc.appstate.edu sent:
>
> Make one. Weld or solder a heavy threaded rod onto the bottom end of a
> spring and attach a weight in the center, then add large nuts to the
> threaded rods until you reach resonance. The only detail that you must
> take care of is to make the system rigid and reasnoably well centered.
>
> We have a picture of ours on the web:
>
> http://www.physics.umd.edu/lecdem/services/demos/demosg2/g2-41.htm
>
> The large plates can be replaced by a bunch of nuts.
>
> Dick Berg
>
> On Fri, 4 Oct 2002, Scott Shelley wrote:
>
> > Hi there,
> >
> > We've lost our Wilberforce Pendulum in our recent move and Sargent-Welch no
> > longer carries one. We need it by Monday at the latest. Can someone let
> > me know where I can purchase one on short notice??
> >
> > Scott
> >
>
> ***********************************************************************
> Dr. Richard E. Berg, Director Phone: (301) 405-5994
> Lecture-Demonstration Facility FAX: (301) 314-9525
> Department of Physics e-mail reberg@physics.umd.edu
> University of Maryland www.physics.umd.edu/lecdem
> College Park, MD 20742-4111
> ***********************************************************************
> Eschew obfuscation.
> -Joseph A. Ecclesine
> ***********************************************************************
>
>

***********************************************************************
Dr. Richard E. Berg, Director Phone: (301) 405-5994
Lecture-Demonstration Facility FAX: (301) 314-9525
Department of Physics e-mail reberg@physics.umd.edu
University of Maryland www.physics.umd.edu/lecdem
College Park, MD 20742-4111
***********************************************************************
Eschew obfuscation.
-Joseph A. Ecclesine
***********************************************************************

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