There are physics problems to be done. Schaum's book is always with me in my studio. These days my mundane work load is so high that I don't get to do more than one or two at a session. Late at night I apply myself to a problem about sliding blocks or friction or banked turns or spinning things or orbiting satellites and gravity. I'm still in the Newtonian world and will be for at least another year, probably much longer.

I attempt to remember the relevant formula, along with some of its derivation. I don't want to think of myself as an unimaginative student who just memorizes formulas to get by, but sometimes that's what I am. Once I have the formula in mind, I plug in the numbers, or get a number which I plug into another formula to get the one the book's problem asked for. Having written it down, I then pull aside the paper I use to mask the answer.

Schaum's gives you the answer right after the problem, rather than having you look it up in the back. Sometimes you have to look at the answer in order to look at the relevant diagram, due to how they have printed problem, answer, and diagram on the page. This can kill the suspense, so I try not to look at it or put a piece of paper over it. But it usually doesn't work, so I have had a glimpse of the answer. I try to forget it while doing the problem, but most of the time it is still tantalizingly on the edge of my memory.

When I unmask the answer, it shows my answer to be wrong. On rare occasions, my answer is right the first time. I am usually astonished and relieved when this happens. But most of the time my answer is wrong. Why is it wrong? Schaum's doesn't work through these practice problems the way it does in the text. I have to carefully go back through all the formulizing and calculating I've done to find out why it didn't match the answer (which in Schaum's well-proofread text, is always right).

Many times I find that it isn't my physics, but my calculation that is wrong. I have copied wrongly, or missed or transposed a number here or there. Or I have forgotten that in some problems I am using the British (feet, inches, pounds) system rather than the metric system. (My Mars probe would be lost.) More often, I find that I have not converted units, for instance that I am using miles per hour instead of feet per second. There are other problems that I simply haven't understood. I save those for later, since they can be discussed with an advisor when it is possible to contact him.

Finally, after some re-calculation, I find an answer that is more or less the one in the book. Time to move on to the next problem, number 5-49. None of these problems are solving anything about a specific real-world question facing me. Their data are all given by the book's authors, not the results of any experiment I have done. The problems are all about simulated, ideal situations. They have no meaning for the world and have no practical use. But I work on them nevertheless, on a long winter night.

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