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Study Hint: More Problems to Study With

The labs, unassigned homework problems, problems found on the web, problems found in other introductory physics texts, problems found below, problems found in the records of other professors' quizzes and exams for related courses are also good sources for practice exam problems, if you manage to get to where you can do all the assigned homework and quizzes and exams perfectly and are still hungry for more problems.

You will find that a lot of these sources contain problems that are surprisingly alike. The same general elementary physics problems are recycled or reinvented from year to year, book to book, professor to professor. It simply is not possible to come up with a Bernoulli's equation problem (to pick just one of a myriad of examples) that does not look much like all the rest, once you strip the ``story'' down to its essential elements. The story ``frame'' can be dressed up differently (beer vs water vs liquid sodium can flow from a keg or a pump or in the cooling system of a nuclear reactor) but it is still basically fluid flowing under pressure uphill and/or downhill through pipes of varying sizes. Similarly, how many different kinds of inclined plane problem or pulley problem can one really encounter? With or without friction, rolling or sliding, with or without a massive pulley - even a plane with or without a pair of masses and a pulley - but these are all easy variations to handle, with just a bit of practice.

It is a good idea to do a few of almost any kind of problem or work your way through a set of problems that explore different aspects of a given topic or concept, but once you get the idea, go on to the next concept. Don't waste a huge amount of time studying constant acceleration motion when you already know it and don't expect more than one or two questions on the exam on it.

While studying for the final (as in all things in life) remain aware of the cost/benefit of your efforts. Spend your time where it is likely to have concrete benefit. We don't deliberately make up exams to punish you - we tend to draw most of the questions from the things that are the most important in a totally straightforward way, and include one or two on the ``esoteric'' topics or more difficult problems to see who is really good and perhaps deserves an ``A'' thereby.

In a medical career, a common aphorism is ``if you hear hoofbeats, think horses, not zebras''. This is intended to remind a physician that most of the time, patients presenting with symptoms that belong both to (say) the common cold and the ebola virus are likely to have the former (at least in this country - in Africa one might well think zebras). It's harmless to be aware of the latter possibility, but focus your energies on the likely outcome.

In physics, a similar analysis would have you focus the bulk of your study energies on the bread and butter problems of the course - Newton's Law (second, of course) in any of a dozen contexts, energy conservation, torque and rotation - and less on the single-topic chapters. After all, you'll need Newton's second law and/or energy conservation or momentum conservation on more than one problem - I guarantee it. You might have a problem on Archimedes' Principle, on thermal expansion, on shear stress and shear strain (and collectively you're nearly certain to have a problem on one of them) but with only eight problems there will be topics with no coverage or coverage only in a short answer MC or T/F question.

Obviously, I don't recommend going into the exam knowing anything less than everything, but when it comes to recommending study focus, clearly you're better off ensuring that you do well on Newton's Second Law than on Archimedes' Principle. In fact, you very likely would be unable to do a lot of Archimedes' Principle problems without also knowing Newton's Second Law and how to use it! Basics first, then add on the specific, topical laws and applications (which, if you think of it, is precisely how the entire course was developed).









next up previous contents
Next: Conclusion Up: Overview Previous: Study Hint: Some Things   Contents
Robert G. Brown 2000-12-09