For as knowledges are now delivered, there is a kind of con- tract of error between the deliverer and the receiver; for he that delivereth knowledge desireth to deliver it in such a form as may be best believed, and not as may be best examined; and he that receiveth knowledge desireth rather present sat- isfaction than expectant inquiry. |
Francis Bacon |
Many students approach a science course with the idea that they |
can succeed by memorizing the formulas, so that when a problem |
Section 0.3 How To Learn Physics 25 |
is assigned on the homework or an exam, they will be able to plug numbers in to the formula and get a numerical result on their cal- culator. Wrong! That’s not what learning science is about! There is a big di erence between memorizing formulas and understanding concepts. To start with, di erent formulas may apply in di erent situations. One equation might represent a de nition, which is al- ways true. Another might be a very speci c equation for the speed of an object sliding down an inclined plane, which would not be true if the object was a rock drifting down to the bottom of the ocean. If you don’t work to understand physics on a conceptual level, you won’t know which formulas can be used when. |
Most students taking college science courses for the rst time |
also have very little experience with interpreting the meaning of an equation. Consider the equation w = A/h relating the width of a rectangle to its height and area. A student who has not developed skill at interpretation might view this as yet another equation to memorize and plug in to when needed. A slightly more savvy stu- dent might realize that it is simply the familiar formula A = wh |
in a di erent form. When asked whether a rectangle would have a greater or smaller width than another with the same area but a smaller height, the unsophisticated student might be at a loss, not having any numbers to plug in on a calculator. The more ex- perienced student would know how to reason about an equation involving division — if h is smaller, and A stays the same, then w |
must be bigger. Often, students fail to recognize a sequence of equa- tions as a derivation leading to a nal result, so they think all the intermediate steps are equally important formulas that they should memorize. |
When learning any subject at all, it is important to become as |
actively involved as possible, rather than trying to read through all the information quickly without thinking about it. It is a good idea to read and think about the questions posed at the end of each section of these notes as you encounter them, so that you know you have understood what you were reading. |
Many students’ di culties in physics boil down mainly to di - |
culties with math. Suppose you feel con dent that you have enough mathematical preparation to succeed in this course, but you are having trouble with a few speci c things. In some areas, the brief review given in this chapter may be su cient, but in other areas it probably will not. Once you identify the areas of math in which you are having problems, get help in those areas. Don’t limp along through the whole course with a vague feeling of dread about some- thing like scienti c notation. The problem will not go away if you ignore it. The same applies to essential mathematical skills that you are learning in this course for the rst time, such as vector addition. |
Sometimes students tell me they keep trying to understand a |
26 Chapter 0 Introduction and Review |
                certain topic in the book, and it just doesn’t make sense. The worstthing you can possibly do in that situation is to keep on staring at the same page. Every textbook explains certain things badly — even mine! — so the best thing to do in this situation is to look at a di erent book. Instead of college textbooks aimed at the same mathematical level as the course you’re taking, you may in some cases nd that high school books or books at a lower math level give clearer explanations. |
Finally, when reviewing for an exam, don’t simply read back |
over the text and your lecture notes. Instead, try to use an active method of reviewing, for instance by discussing some of the discus- sion questions with another student, or doing homework problems |