Re: Fwd: The Concrete Wheel

Duncan Chiu (
Fri, 02 May 1997 17:44:49 -0400 wrote:
> I think that I know the answer but I will check and wait until others have
> time to think about it.
> ---------------------
> Forwarded message:
> To: RFORMAN639@AOL.COM (Ron Forman)
> CC: irafrdmn@AOL.COM (Ira Friedman), (Eric Forman),
> (Fred Sawin), (J.C.
> Thompson), (Brenda Timmerman), (Jan Smith),
> (Jack Arnow), (Frits Pleiter)
> Date: 97-04-30 05:10:33 EDT
> [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?


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?