RE: supplementary S.I. units

[Joe Baughman <joebau@blueridge.cc.nc.us>]

At 03:24 PM 9/22/98 -0600, you wrote:
> Is not the radian defined as a ratio of arc length to radius, and as such
> all
> unit cancel !!??
> Oren Quist, SDSU

I think the "dimensionless unit" is one of the points of this discussion.
When everything cancels out, the student is left with a "unitless"
answer-and thus some confusion arises as to the unit of the answer (ie, the
answer may be in "radians").  

Some of my students "wonder"  about this after I have pushed and pushed
about the use of "unit analysis" to facillitate the solutions of problems.

Thus, the idea of a "radian" as a base unit intrigues me as a possible tool
to use in helping the student to grasp what is going on.

I admit that I don't delve into the scientific implications of using a
radian as a base unit.  My real interest is in helping students understand a
little bit more about our world.  Most of the students I have have in
physics never have taken chemistry or physics in high school nor, for that
fact, taken more than two years of math (usually have Alg 1 and Geometry).
We do have a pre requisite of College Algebra to take physics, but if I
insisted on this, I would have no students at all.  Around here we have
problems having students take physics in high school much less in a
community college.

I shall think about this some more and I appreciate all the discussion on
this board.  
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Joe Baughman                              e-mail:  joebau@blueridge.cc.nc.us
Science & Mathematics Instructor
Blue Ridge Community College           Telephone: (704)692-3572 x301
College Drive                                Fax: (704)692-2441
Flat Rock, NC  28731-9624

                 Web Server:  http://www.blueridge.cc.nc.us/
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