Date:         Mon, 12 Jul 1999 13:51:36 -0400
Reply-To:     Martin Jagersand <jag@CS.YALE.EDU>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Martin Jagersand <jag@CS.YALE.EDU>
Subject:      Westy brainteaser answer and saw some Westys FS.

I just came back from this weekends kayaking and climbing trip.
Saw some westies FS on the side. More details below. To everyone
who has p-mailed me (for parts or other things), I'll get back to you
as soon as I can, but might take a couple of days to get through
all the emails.

Now to the Westy brainteaser. The question was if you park 25 Westies
on the middle of the Golden gate bridge make the mass centrum of the
bridge (alone) move up or down?

The listees whose p-mail I've read so far all got it right and had
good motivations for the answers, and in fact did overall better than
the sample of Yale students I tested the question on. Here's my suggestion:

Answer: Up. The Golden gate bridge is a suspension bridge, whose
supporting cables form a curve approximately like a chain hangs (*) when
suspended from its two endpoints. The 25 campers act as a force displacing
the middle of the bridge downward somewhat, say d meters. This adds the
energy d*25*2000kg. By preservation of total energy the bridge mass center
goes up approximately d*25*2000/m_bridge, where m bridge is the bridge mass.

(*) Catenoid curve. The exact curve is not important however, just the
assumption that the energy is being conserved through the movement of connected
masses, not through e.g. material elasticity.

Now to the Westies I saw. They are in the lot next to the deli just down the
hill from the climbing wall in the Mohonk preserve in the 'Gunks, NY State.
Presumably the vehicles/houses of climbing bums who made it there, but not back
again. All were late loaf Westys. Two of the three looked pretty rough. The
third looked ok. The phone number on the sign was half worn off, so
I couldn't read it. The people in the repair shop whose lot they are
on probably know the scope, but I was there on a Sunday and it was closed.
Someone who goes climbing weekdays could check.

/Martin
--
Westy 1.9l Turbo Diesel
Quantum 1.6l Turbo Diesel

New and used parts for sale, gas and Diesel:

    http://www.cs.yale.edu/~jag/vw/forsale.html

Martin Jagersand                 email: jag@cs.yale.edu
Computer Science Department             jag@cs.rochester.edu
Yale University

        Slow down and visit the VW diesel Westy page:
          WWW: http://www.cs.rochester.edu/u/jag/vw
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