Re: [Phys-l] formatting uncertainties

["Kilmer, Skip" <kilmers@greenhill.org>]

Did you mean outward. I think an object moves in a circle because a real force pushes it inward. ;<)

-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu [mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of John M Clement
Sent: Wednesday, January 23, 2008 4:07 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] formatting uncertainties

> This reminds me of our old discussion on centrifugal force. It is a
> no-no in HS physics meaning that a student is penalized in the
> (external) exams if he/she uses it e.g. in solving a problem. Of
> course, it does not harm students if they are told a bit about
> centrifugal force/inertial forces in the context of non-inertial
> frames once they are comfortable with forces in inertial frames.
> It might harm them if they leave HS with the belief that centrifugal
> force is evil and should be avoided at any cost :-).

This has been around before and stirs up a honets nest.  But
essentialy this is correct.  Actually they need to be able to analyze
in terms of actual physical forces so I always say that centrifugal is
just a name meaning inward, and I ask if there is anything pushing
inward.  If the persist I will tell them that the word is often used
for a "pseudo force" (in this age the word virtual might be better),
but that from our class point of view there is not such thing.  Since
many of my students never get to a point where they reliably identify
and use forces correctly, there is no hope of talking more about
"centrifugal force".

John M. Clement
Houston, TX
_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l