🚀 go-pugleaf

Brion G. Patterson (bpatters@PEN.K12.VA.US) wrote:
: Are people using graphing calculators in introductory physics
: classes?  My students now all have them, I haven't used the
: capabilities of them, and I'm not sure if I want to.  It seems
: that basically with the graphing calculators you start with the
: equations as given, instead of deriving them ( or maybe it
: doesn't have to be "instead" but that seems sort of the gist of
: it).
: So what are folks doing?
: -Brion

I see a few with $250 HP48GX's, a bunch with TI81 through TI85, and 
the majority with much cheaper calcs. At Drexel, we get them to 
try Maple V and Excel for calculations and graphing. 

Generally, these calculators seem like toys with frills. None of my students
has really used the stuff.

However, one thing is really useful, and that's the multi-line display.
All calculators should have these things, but I don't think that
freshmen need to spend more than $100 for it...


Chuck
(Grad Student and Physics TA, whose wife wouldn't let him buy a HP48GX...)

 Last fall, in an introductory calculus-level physics class, I gave a
problem similar to one I'd given in the past, but not for a few years.
I defined a potential energy function U(r) = a/r^2 - b/r, where a and b
were positive.  The problem eventually asked for the force function
F(r), the equilibrium points, whether the equilibrium is table or not,
etc.  But the first part asked the students: "(1).  Make a rough
(qualitative sketch of what this function looks like."  Included was a
pair of axes labeled U(r) and r.  This type of question never gave
students much difficulty in the past.  I expected them to see that at
r=0 the U(r) approached positive infinity, and at infinity U(r)
approached zero from the negative side, with just a single minimum in
between.  To my amazement, the students complained bitterly about the
unfairness of this questions, saying, "You can't do this without a
graphing calculator."
  Of course, this was the first class I'd encountered that had used
graphing calculators in high school.  Now they are to be used in our
calculus courses here.
  I give written exams, no formula sheet, no calculators.  The questions
with numerical answers are to be estimated.  In class I don't use a
calculator either (I used to bring in a large solar scientific
calculator), but estimate numbers.  Of course, homework problems include
heavy use of calculators or computers.

 Laurent Hodges
 





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