Expert: Philip A. Stahl - 2/20/2011

Question
Hello,

I was wondering if you could provide some advice on how to solve problems.When solving problems i always solve it the trivial way, the only way i know how to.I usually follow the procedure outlined in the examples of the book. I rarely am able to come up with a solution myself that is correct/ without looking at the solution manual.

When i see the solution to a problem, i usually say,"i would never have thought doing that."

It sounds like im just following a recipe. But i do read the book aswell, and use the worked examples as templates.

I need help learning how to come up with more complex solutions my self. I also tried to practice many questions but no avail. I think i am missing something.

Lastly how important is interest in learning physics? I usually just study to know how to solve problems so that i can solve similar problems come test time.

What are some ways of developing interest?

thank you

Answer
Hello,

You don't really specify what physics subject you are dealing with, whether General Physics, or astrophysics, or a detailed individual physics course (e.g. thermodynamics, modern physics, electricity & magnetism) hence it is hard to formulate a precise way to address your query.

However, on the assumption you are doing General Physics, the best problem solving guide I've found is 'Feynman's Tips on Physics' which ought to be available at Canadian Amazon.com.

He goes into not only the sort of reasoning with which you want to approach problems, but also problem solving techniques (more than I could ever do justice to here, in the limits of a single question, answer). See, for example, his Chapter Three: 'Problems and Solutions'.

Generally the key in solving any physics problem is first asking WHAT is it that you need to find (it helps to write everything down, including the units) and what principle is underlying the question or problem? Once you can establish the principle, it's then usually straightforward (by virtue of listing all the known data of the problem) to arrive at a coherent and consistent approach to the solution.

If a specific relationship is needed, the good student will be able to put together the assorted information from the problem and then solve it.

If, on the other hand, you see an actual solution and say to yourself 'I'd never have thought of doing that', then it likely means you didn't really grasp the principle the first time. Hence, the solution came as a surprise.

Again, this is why Fenyman's Guide book is probably the ideal item to obtain to help you in really solving problems - and his problems and examples occupy far more space than I could possibly devote to here.

As for interest in learning physics, say as an adjunct to solving physics problems, I'd say extremely important! Otherwise, you approach it merely like a bunch of recipes (or equations) to crank out what you need, without understanding what it is you're doing.

My suggestion to past students has been to see how real physics works! I can't speak for Canada, but here in the U.S. there's no end of science, physics programs on TV. For example, the Discovery SCIENCE channel. On any given night one is sure to find some subject to whet one's interest - whether satellites (related to circular motion, gravitation), or electronics, or thermal aspects to do with greenhouse effect.  If you have such fare in your area, I'd strongly endorse viewing some of it to get your interest in learning ramped up.  (Especially needed if you're taking physics as a pre-requisite, but your actual field is going to be biology, medicine or some such ) Also - keep your eyes peeled for the series called 'The Mechanical Universe' which is WELL worth your while.

Lastly, there are always good magazines you ought to be able to get, written at the popular level. Over here we have 'Physics Today' and "New Scientist" both of which provide numerous entertaining insights and articles on recent physics developments.

Feel free to ask more specific questions if you need to. Otherwise, your best bet is Feynman's Tips on Physics!