
Physics Problems to Challenge Understanding - rndn
https://www.lhup.edu/~dsimanek/scenario/insight.htm
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decisiveness
> Today many students want everything "spelled out". They seem to be
> continually looking for "defects" in problems, but not with the purpose of
> furthering their understanding by coping with ambiguity, but to provide an
> excuse for not even thinking further about the problem.

But shouldn't the burden be put on the educator to provide problem scenarios
for understanding that aren't unrealistic? It just seems common sense to
develop an uninterested attitude toward things that start out trying to prove
by understanding a thing that could never happen.

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banachtarski
I don't think so. Reality is always harder to model perfectly so the
"unrealistic" problems are actually more approachable. When you compute the
terminal velocity of a falling object, I assume that the first attempt assumes
a vacuum, no fluid resistance, no relativistic effects, etc. (edit: and then
there's the coriolis force, the azimuthal force, radiation pressure,
electromagnetic forces, etc.)

Posing problems that sidestep how nature might actually behave allows the
educator to isolate concepts for the student and improve proficiency (before
adding higher order perturbations).

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krick
I briefly scrolled through some parts and have a mixed feeling. Like it's
interesting, but I'm not sure I believe it. Consider the tug-of-war riddle. On
the first thought the suggested answers seem correct and somewhat insightful.
But now forget it and try to visualize the contest how it _really_ is. Imagine
one of the participants being clearly stronger than another, imagine different
weight classes, imagine one wearing slippery shoes and the other nice rigid
boots. What I discover thinking of it is that however good friction with the
ground is clearly huge advantage, it isn't what actually let's participant to
win: the whole contest isn't that much about moving the _atomic object_ , the
_whole person_ , it's actually about moving its center of mass past the point
of his feet touching the ground. Then, indeed, the winning person will exert
greater force than the other against the ground, and the losing one will be
basically flying.

Reflecting over it I feel that however what author suggests formally is the
right answer and the right strategy to think about the problem, the whole
problem as it's described in the second, "more open-minded" fashion is
simplification beyond being justifiable. When I'm supposed to give an answer
like that I'd strongly prefer problem being defined in strict scientific
terminology, without all these silly "Arnies" and "Wimpies" and "thug of war",
which, admittedly, makes the "supposed answer" pretty much obvious. Because
the _real_ thug of war just isn't happening between two atomic objects and I
would feel very uncomfortable accepting this all-too-abstract model. Abstract
models are good and useful only inside the boundaries where the predicted
results actually match the reality, when it's untrue — the more complex, more
realistic and less abstract model has to be applied.

And that's basically the problem with all that approach, when author ignores
the fact he's stretching the model he wants to be applied a bit too damn far
and hopes that students would neglect it and follow his lead basically
guessing what _he_ was thinking when designing the problem. I don't think this
is how science should be done. Because science, originally, isn't about
solving riddles: it is about describing and interpreting perceived reality.
And, well, having intuition about the physical reality is pretty damn
important.

So I rather empathize with those `continually looking for "defects" in
problems`, because they still believe the reality is what happens on the
street, not in the professor's imagination.

~~~
banachtarski
When I read that problem, I immediately discarded answers A and B because they
are just wrong. Strength and such would have absolutely no affect on violating
Newton's third law. It seems like you are waffling in your intuition of the
problem which suggests that this problem has revealed an actual problem in
your understanding of the fundamentals (which means it is a well designed
problem).

There is no stretching of the model or anything happening. Even if you account
for higher order effects, A and B would still not be true.

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tempodox

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      You do not have permission to view this directory or page using the credentials that you supplied.
    

This is not a Physics problem, it's a server configuration problem.

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scottmcdot
These are excellent! Thanks!

