> 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.
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).
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.
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.
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.