Fall 2004 Physics 170
Study Suggestions and Problem Solving
- Keep good notes. Use the text to fill in lecture material. The
act of writing material down helps to cement the ideas in your brain.
- You must work problems; this is how you learn physics.
Think of it as working out, just like pumping iron (but a lot less
repetitive!). As in learning a language, one `gets' the concepts by
speaking and not just by listening. You cannot learn to surf by
watching videos, and one cannot learn physics without thinking the
concepts through. There is more to it even than just becoming facile
with the specific concepts: physics is a way of thinking about and
approaching the world. One learns this through a kind of
apprenticeship approach, familiar to many disciplines.
- Do not get bogged down in units. Keeping track of units
in solving problems is very useful, and dimensional analysis
[figuring out what dimensions (say, length/time) the answer should
have, and thus something about the form of the equation which will
give that answer] is a very powerful tool. But, conversion
constants and the like can always be looked up. Still, one needs a
few benchmark numbers at one's fingertips in order to have a feel
for when one has the answer roughly right or off by some huge
- There are many many equations. Don't try to remember
all of them. Learn a few of the fundamental equations. You may
want to keep a summary sheet of these, which will be useful at test
time for your "cheat sheet".
- Study a little every day. Set aside some definite
hours, and do not focus upon how much you need to get done. Just
work diligently for the allocated time. You will always find that
it takes longer to read the book, do the problems and such, than you
thought it would. Don't get too far behind and allocate more study
time after a week or so if you are slipping.
- Physics is a quantitative science, which means that
things can be calculated numerically. Sometimes these calculated
results can even be checked experimentally to very high precision.
The way that we learn physics is by problem solving. Problem
solving is an art which must be mastered in order to do well in the
course. This skill (quantitative reasoning) will also be useful in
many other fields, from engineering to finance to making sensible
decisions as a consumer and citizen of an increasingly technically
- We teach problem solving in several ways:
- Class Examples: We will work examples in class. Follow
- Book and Study Guide Examples: Many examples are
provided to aid the student. See the User's Guide in the front of
the text to see how the book provides insights and strategies to
help you become good problem solvers.
- Homework: This is your chance to practice what you have
learned. Homework is collected and graded weekly and is weighted in
your grade. You can probably copy someone else's work, which we
greatly discourage, but you will ultimately be the loser if you do
so. It is not a bad idea to work together as a team on the
homework, if you wish. Often peers can learn much from each other.
However, there is the danger of becoming dependent on whichever team
member is quickest at problem solving.
- Homework instructions:
- Use 8 1/2" x 11" notebook paper. Keep your old homework
in a binder for study purposes (and who knows you may be a grader
later yourself!). Use only one side of the paper.
- Staple your sheets together and fold them in half the
long way. Put your name, social security number, and problem set
number on the top right side of the first sheet (inside) and on the
top right side of last sheet (outside).
- Neatness does count. The grader can't give partial
credit if he/she can not read your paper. Sloppy work often reflects
- Use a reasonable number of significant figures for your
numerical answers. You will be graded down for ridiculous accuracy.
Writing down an answer as 3.999999999 when the number is really 4
for all practical purposes is not just lazy, it shows a lack of
understanding that one does only measure things usually to a few
decimal places. Indeed acquiring some sense about how much accuracy
is need is important to the physics, and vital to engineering and
many other practical matters.
- If you do not see how to do the job intuitively, then try to
follow the recipe below when doing problems:
- Paraphrase the problem (briefly): write it out in your
- Draw a diagram and label it. Diagrams are often
crucial; problems without diagrams will usually be graded down.
- Write down what is given and what to find.
- Write down the relevant formulae. Use symbols at this
stage, except for constants.
- Reorganize the formulae to get the desired unknown on
the left of the equal sign and the known quantities on the right.
- Rewrite the equation with numbers and units inserted.
- Write the solution with units and put a box around it.
Be sure that you use vectors and scalars properly when writing your
last revised 20 August 2004