Re: [Phys-l] A simple (?) question about speed

[Jack Uretsky <jlu@hep.anl.gov>]

Hi all-
	Here is a conjecture, based on recent miscommunications with 
adults (including a judge and a lawyer).  Many people pick up words, and 
remember them, without remembering them in a particular context.  Thus, 
such a person who has attended a lecture in which the word ``constant'' 
was used, would remember the word independent of its meaning.  More 
precisely, the remembered context of the word would be the environment 
where it was heard (the physics class).  So a question that the person 
doesn't understand, asked in that class, would have a high probability of 
giving rise to a recently heard, and not understood, word, namely, 
constant.
	This hypothesis is easily tested by the judicious use of synonyms.
					Regards,
						Jack


On Tue, 11 Sep 2007, Robert Cohen wrote:

> In response to my post, John Denker asked:
>
> > Is this a question about _speed_ ... or is it a question
> > about the meaning of _constant_ and its relationship to
> > _initial_ / _final_?
>
> And John Barrer asked:
>
> > What was the rationale the students gave who chose "C"?
>
> I don't have a list of their rationales.  An informal poll of just a
> couple students, as part of the classroom discussion, revealed that some
> were thinking acceleration instead of speed, since we had been
> discussing constant acceleration and what it meant to have a constant
> acceleration vs. a non-constant acceleration.
>
> Thus, I suspect they would have answered this correctly prior to being
> introduced to acceleration but I don't know.
>
> As for the meaning of initial and final, I believe students have
> difficulty with that as well but they didn't mention that during the
> discussion.
>
> John Barrer also asked:
>
> > I
> > wonder if the answers would be different if the question were
> > reframed with a familiar context. "A car has an initial speed
> > of 30 mph and a final speed of 60 mph". Same thoughts
> > vis-a-vis the question posed later. Is the use of a vague
> > and/or context confounding the results?
>
> That is an interesting question.  If anyone tries it, I'd be interesting
> to know what happens.
>
> ----------------------------------------------------------
> Robert A. Cohen, Department of Physics, East Stroudsburg University
> 570.422.3428   rcohen@po-box.esu.edu    http://www.esu.edu/~bbq
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