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Re: [Phys-l] Q: Why are manhole covers round?



Why is a moth attracted to light? Is it because they love light and want to bask in its glory or because they hate it and want to attack it?

----- Original Message ----- From: "Bernard Cleyet" <bernardcleyet@redshift.com>
To: "Forum for Physics Educators" <phys-l@carnot.physics.buffalo.edu>
Sent: Sunday, May 21, 2006 12:11 AM
Subject: Re: [Phys-l] Q: Why are manhole covers round?


I suppose that's why triangular ones are hinged.

bc, first quizzed on this by the late Ron Ruby in 1984.

p.s. any constant diameter figure will work e.g. Rouleaux triangle.

John Clement wrote:

It is probably because you do not want the covers to accidentally fall into
the hole. A square one can be oriented so as to fall through, but a round
one can not.

This reminds me of the question "Why do gorillas have big nostrils?" The
answer is because they have big fingers.

John M. Clement
Houston, TX



A: Because the manholes are round.


(Something to keep in mind when discussing "cause and effect".)




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_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l