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Re: Mass




One only has to have faith if you understand the distinction, but do not
understand Einstein. In the case of HS the vast majority do not even
understand the issue, so when they see m in two different equations it is
not a problem for them to think that it is the same thing. The real problem
is that they might think that the m in the gravitational equation is a
completely different quantity from m in NTN2.

Remember that 80% of HS students are not formal operational so such fine
distinctions are usually beyond them. Indeed, below the formal operational
level understanding of 3 variable equations such as F=ma is quite elusive.
If you don't believe what I say, then perhaps you should read Shayer and
Adey "Really Raising Standards", and then pursue some of the Piagetian
literature that they reference.

Therefore the definition of mass as what is measured by a balance is
probably the only good definition for most HS courses, and the majority of
intro. college courses.

One of the reasons why they can believe is outrageous things is that they
have memorized so much stuff in school that they don't really believe. So
why should they believe the sensible things they are told??? Without the
exploration to validate the math and science ideas, all they have is
memorized factoids.

John M. Clement
Houston, TX


"Perhaps it is better to define mass as: what a beam balance measures
while
at rest in a gravitational field.

Fred Bucheit

~ I think is the antidote to I believe~"



but that's only 1/2 of it as others have written. What is impt. (I
pray.) is that, as one mentioned, both are the same #. Why was an
accident until Einstein "said" they had to be the same * . We've
already had a thread(s) on Eötvös.

Just one of the things HS students must believe (have faith). That
shouldn't be difficult as so many believe in much more outrageous things.

bc

Ludwik Kowalski wrote:

I think that for an introductory physics course
Fred's description is much better than what I wrote.
Ludwik Kowalski


On Monday, Oct 18, 2004, at 20:27 America/New_York, fred bucheit wrote:



Perhaps it is better to define mass as: what a beam balance measures
while
at rest in a gravitational field.

Fred Bucheit

~ I think is the antidote to I believe~





From: Brian Whatcott <betwys1@SBCGLOBAL.NET>
Reply-To: Forum for Physics Educators <PHYS-L@list1.ucc.nau.edu>
To: PHYS-L@LISTS.NAU.EDU
Subject: Re: Mass
Date: Mon, 18 Oct 2004 19:09:40 -0500



Brian Whatcott wrote:



Mass is the name given to the resistance observed when
attempting to change the linear speed of some coherent object
which is otherwise perfectly free to move.


At 06:45 PM 10/18/2004, Cliff P., you responded:



What is the name given to the resistance observed when attempting to


change


the direction of a moving object which is otherwise perfectly free to


move?


When push comes to shove I tell my students that mass like charge is
something that "stuff" has.

Cliff Parker


I realize it may be difficult to swallow in the physics paradigm, but
the
description given above is in fact, adequate.
To change direction is to impart a change of speed in some direction



Brian Whatcott Altus OK Eureka!


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