Re: A question about Calc-based physics content

[DSCHROEDER@cc.weber.edu]

> The question then is how to do it well.  One solution is to keep doing 
> what we have been doing, insert some ideas from calculus in our 
> discussion of motion, and call it a calc-based course.  I'm not too happy 
> with such a facade.  The other solution is to cut topics which are not 
> needed by the chem or bio majors, or might be covered in physical 
> chemistry.  The situation is, of course, complicated by the 
> "less-is-more" thinking associated with developing good conceptual 
> understanding in an active classroom.

I agree that the term "calculus-based physics" is largely a facade.
Sure, we use some calculus on the blackboard in front of the students,
and the book is full of integral signs, but what counts is the 
homework problems, and very few of the problems in Halliday and
Resnick require the use of calculus.  Those that do are artificial
and contrived, like giving some ridiculous polynomial function for
x(t) and telling the student to take its derivative (symbol-pushing)
to find v(t).

On the other hand, I think it helps students enormously to be taking
or have taken calculus.  A calculus course can make them more comfortable
with concepts such as instantaneous velocity and work done by a varying
force.

> 1) If you teach such a course, what strategy do you use, and how well 
> does it work?

My strategy is to use calculus language in the classroom only when
absolutely necessary.  I talk a lot about sums and areas but hardly 
ever write integral signs.  I try to make it very conceptual, and
I assign problems that test concepts and de-emphasize symbol pushing.

> 2) Do you leave out material that you know will be covered by others, 
> thermo would be a good example, since it is done in physical chemistry?

No, thermodynamics is too important, and I don't trust chemists to do
it right.  On the other hand, I do leave out most of atomic physics,
figuring that if I can get students to understand what a wavefunction
is, then the chemists can have the task of drawing all the wavefunctions
for a hydrogen atom.

> 3) How seriously do you use the calculus in your course?

See (1).

> 4) What do you generally leave out, and what do you emphasize.

I leave out heavy-duty calculus like integrals to calculate fields of
continuous charge distributions.  I leave out phasors and most AC
circuits and capacitance for any geometry except parallel plates
and most of atomic physics.  I vector cross products out of rotational
motion, treating only rotation in a fixed plane.  I leave out a lot
of geometrical optics.  And I leave out those superficial chapters at
the end of the book on solid-state physics and "quarks, leptons, and
the big bang".  I do cover nuclear physics in some depth.

By the way, our course has four lectures and one recitation session
per week, so it's pretty intensive.  We're confined to a one-year
course because few of our constituents would tolerate a longer course.

-dan