Problem Solving Guidelines
The following general guidelines are intended to help you learn how to
approach the more advanced problems you will encounter in this class.
These techniques should apply equally well in other Physics courses.
I have developed these techniques through my experience. There is
no single way to solve problems; if you have already developed some methods
that work for you, then by all means, stick with them. But for those
who feel they are struggling a bit, I hope these guidelines will help you
get moving in the right direction. I'm sure that once you gain some
experience with solving problems, you will also develop your own personal
Of course, many problems are different, and don't require you to solve
the equation of motion, but instead to apply some other derived results
to a specific case. In these situations, there are often new terms
that are used, and you should have a good understanding of what they mean.
It may be helpful to write down a "vocabulary list" in these situations.
Carefully read the statement of the problem.
Make a diagram(s) for the problem. Include any objects, forces, and
motions mentioned in the statement of the problem. Artistic quality
is not an issue, as long as you can visualize what is occuring through
Set up a coordinate system for the problem, especially important for more
complex 2 and 3 dimensional problems. You may need to choose a non-cartesian
fixed, inertial (x,y,z) coordinate system (cartesian)
fixed, inertial (r,[theta],z) coordinate system (cylindrical)
other possible inertial coordinate system, for instance spherical
non-inertial coordinate system
Evaluate the forces in your chosen coordinate system, and write down the
equations of motion, F = ma . Remember to include
fictitous forces if you use a non-inertial coordinate system, and write
down the correct form for a = d2r/dt2if
you are using a non-cartesian coordinate system.
Solve the equation of motion. If the task looks extremely difficult
or impossible, consider if it might be easier in a different coordinate
system. Try re-reading the statement of the problem, paying particular
attention to your diagram of the problem. If, after 20 minutes or
so, you have made no progress on this problem, leave it and go on.
Come back to it later, perhaps after talking about it with a classmate
or the professor.
Re-check your work for missing "-" signs and "factors of 2".
Feedback is welcome. Send your comments or suggestions to