# Re: Fwd: The Concrete Wheel

Duncan Chiu (dchiu@idt.net)
Fri, 02 May 1997 17:47:19 -0400

Sorry, the ratio is 26,400 : 1.

duncan

Duncan Chiu wrote:
>
> IraFrdmn@aol.com wrote:
> >
> > I think that I know the answer but I will check and wait until others have
> > time to think about it.
> > ---------------------
> > Forwarded message:
> > From: DADKB@CUNYVM.CUNY.EDU (Dan Davis)
> > To: RFORMAN639@AOL.COM (Ron Forman)
> > CC: irafrdmn@AOL.COM (Ira Friedman), ejf2@acpub.duke.edu (Eric Forman),
> > fsawin@hypercon.com (Fred Sawin), thompson@utaphy.ph.utexas.edu (J.C.
> > Thompson), btimmer@isi.edu (Brenda Timmerman), jan@extant.com (Jan Smith),
> > jackarn@juno.com (Jack Arnow), F.Pleiter@phys.rug.nl (Frits Pleiter)
> > Date: 97-04-30 05:10:33 EDT
> >
> > THE CONCRETE WHEEL
> > [This problem is proposed by Victor J. Katz in a book review in
> > the College Mathematics Journal, May 1997.]
> >
> > Suppose you are sitting in a ground level room, facing a square
> > floor-to-ceiling window that is 20 feet on a side. A huge solid con-
> > crete wheel, 100 miles in diameter, is rolling down the steet and is
> > about to pass right in front of the window, from left to right. The
> > center of the wheel is moving to the right at 100 miles per hour. What
> > is the view, from inside the room, as the wheel passes by?
>
> Ira,
>
> How about a fleeting salesman's car? A portion of the sine curve? Or,
> maybe a slow-moving parabola? (It took one hour to clear the object,
> didn't it?)
>
> For those of us who could not visualize a ratio of 52,800 to 1 (wheel to
> window,) try this:
>
> Move the window from right to left along a yardstick taped to the edge
> of a big round table, making sure the stick is slightly higher than the
> table. you can cut a small square off the edge of a piece of paper (that
> is your wall and the window) and slid it along the stick.
>
> What do you say?
>
> duncan