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Re: [Phys-l] [ap-physics] The Swinging Bucket Problem

Because it works for millions doesn't mean it will work for my high-schoolers. The top of the class would be fine with centripetal. The students that are not planning on going into a science field, or for that matter going to college, sometimes need something a bit different than what might be accepted by millions.

If my students go to Dictionary.com & look up centripetal, the first definition they see is:

centripetal force: the force, acting upon a body moving along a curved path, that is directed toward the center of curvature of the path and constrains the body to the path. (there are additional definitions that are a bit more accurate).

They read "THE force" to mean the ONE force that is making this happen. We can all agree this is not true. It would certainly be nice if a single class discussion would resolve this issue, but it doesn't (ok, it does for the top tier, but I can just give the top tier the book & they'd be able to figure it out)..

When we are involved in centripetal forces in class, students use texts, worksheets, labs, websites, and other items that all use the term centripetal force. I tell them that if I hear the word 'centripetal' they will get a detention. They understand that this is a class joke. But they know that I seriously want them to use a phrase like, "net radial force", "total center directed force", or "sum of the forces acting along the radius" in place of centripetal. When we are done, they tend to understand what they can get away with saying in class. They can get away with anything that follows an acceptable definition of centripetal. They know what centripetal means (or at least more so than they might have otherwise).

I haven't done this with any other terms. I might. It has worked pretty well for me and my students. I believe that while they are not allowed to use the term centripetal in class, they have a better grasp of what it means than most businesss people, economists and truckers.




Paul Lulai... where neologism is my new word for the day. Thanks b.c.
Physics Teacher
St. Anthony Village Senior High
Saint Anthony Village, MN
55418
(w) 612-706-1144
(fax) 612-706-1020
plulai@stanthony.k12.mn.us
To wonder is to begin to understand.

________________________________

From: phys-l-bounces@carnot.physics.buffalo.edu on behalf of Bernard Cleyet
Sent: Mon 9/24/2007 3:28 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] [ap-physics] The Swinging Bucket Problem



"... net means total and hope that this name works."

Why buck millions of people w/ a neologism.

Business people, economists, et al. won't agree w/ you, and what about all those truckers that have net weight printed on their rigs.

bc, eschews neologisms, as instructed by Strunk and White.





Paul Lulai wrote:

Normal force is that of two surfaces with the force perpendicular to the
surface.
Friction is a force btn two surfaces due to their contact
Gravitational Force is a a force due to masses attraction for each other
(at the Newtonian level)
Tension caused by a cable etc..

Centripetal force is the only force I can think of that has a name but
means total.
Jack's point that name is 'inconsequential as long as everyone is clear
on your meaning' is true & well-taken. I have gone a similar route to
Dan. I call it the net radial force. I try to beat into them that net
means total and hope that this name works. I suppose it might also work
to put similar effort into defining centripetal. However, it is the 1
exception to the trend of 'named' forces having a singular cause.

I think I first heard Boris K. use net radial to replace centripetal. I
have found it useful with my students.


Paul Lulai . . . To wonder is to begin to understand
Physics Instructor
Saint Anthony Village Senior High School, ISD 282
3303 33rd Avenue N.E.
Saint Anthony Village, MN 55418

(w) 612-706-1144
(fax) 612-706-1140

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




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