Re: Coriolis

[Robert A Cohen <bbq@ESU.EDU>]

On Mon, 9 Aug 1999, Roger Haar wrote:

> Ludwik,
>         I think that beside a clear explaination, a clear
> description of what the Coriolis effect is.  There are good
> videos on this.  (I first really understood the effect in an
> intro meteorology class.)  The video is something like
> this.  Two people are facing each other on opposite sides of
> a turntable, merry-go-round or whatever.  These two are
> trying to throw a ball back and forth. A camera is above the
> center of the turntable.  IF it is fixed to the ground the
> ball goes appears to go straight and the catcher moves away
> from the ball.  If the camera is fixed to the turntable, the
> ball curves away from the catcher.
>         Once it is clear what the effect is, and how it is
> reference frame dependent, the theory is easier.

Just a word of caution: Two forces are acting on the ball, coriolis and
centrifugal.  The example of a ball thrown on a merry-go-round does not
illustrate the effect of the Coriolis force alone.  I say this not to
criticize Roger's example but because such a distinction wasn't clear in
my mind the first time I saw this example and it hunted me for a quite
some time.

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| Robert Cohen               Department of Physics       |
|                            East Stroudsburg University |
| bbq@esu.edu                East Stroudsburg, PA  18301 |
| http://www.esu.edu/~bbq/   (570) 422-3428              |
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