Tips for ProblemSolving in Physics!

Besides what you might expect to learn about physics concepts, a very valuable skill
you should hope to take away from your physics course is the ability to solve complicated
problems. The way physicists approach complex situations and break them
down into manageable pieces is extremely useful. When working
on problems, the secret is to keep your GOAL in mind!
GOAL PROBLEM-SOLVING STEPS
Gather information
The first thing to do when approaching a problem is to understand the situation.
Carefully read the problem statement, looking for key phrases like “at rest” or
“freely falls.” What information is given? Exactly what is the question asking? Don’t
forget to gather information from your own experiences and common sense. What
should a reasonable answer look like? You wouldn’t expect to calculate the speed
of an automobile to be 5
106 m/s. Do you know what units to expect? Are there
any limiting cases you can consider? What happens when an angle approaches 0°
or 90° or when a mass becomes huge or goes to zero? Also make sure you carefully
study any drawings that accompany the problem.
Organize your approach
Once you have a really good idea of what the problem is about, you need to think
about what to do next. Have you seen this type of question before? Being able to
classify a problem can make it much easier to lay out a plan to solve it. You should
almost always make a quick drawing of the situation. Label important events with
circled letters. Indicate any known values, perhaps in a table or directly on your
sketch.
Analyze the problem
Because you have already categorized the problem, it should not be too difficult to
select relevant equations that apply to this type of situation. Use algebra (and calculus,
if necessary) to solve for the unknown variable in terms of what is given.
Substitute in the appropriate numbers, calculate the result, and round it to the
proper number of significant figures.
Learn from your efforts
This is the most important part. Examine your numerical answer. Does it meet
your expectations from the first step? What about the algebraic form of the result—
before you plugged in numbers? Does it make sense? (Try looking at the
variables in it to see whether the answer would change in a physically meaningful
way if they were drastically increased or decreased or even became zero.) Think
about how this problem compares with others you have done. How was it similar?
In what critical ways did it differ? Why was this problem assigned? You should have
learned something by doing it. Can you figure out what?
When solving complex problems, you may need to identify a series of subproblems
and apply the GOAL process to each. For very simple problems, you probably
don’t need GOAL at all. But when you are looking at a problem and you don’t
know what to do next, remember what the letters in GOAL stand for and use that
as a guide.