SOLVING PROBLEMS 

One of the challenging aspects of a physics course is to learn how to solve 
problems . The problems to be solved can be expressed in several forms. 

1. Thought problems - these are stated in the form of "questions. 'After one 
reads the question then one judges the statement of problem and then solves it 
by the application of a physical principle. The process may go like this: After
reading the question one has to ask one or more further questions like " what is
the question trying to find out? What is the problem asking? You may have to 
reread the question and ask: what does the statement of the problem mean? Finally
when you have come to a consensus of what the problem means, one merely applies
a physical law to solve the problem. Often one may select the wrong law and that
may result in a wrong solution. All the while you are in the process of solving
the problem, keep asking: " does this answer make sense? " 

2. Quantitative problems- these are the statements of several values of physical
variables with the request to find the value of an unknown. Often, one does not
comprehend that something can be predicted from a knowledge of known values. This
- is one of the unique properties of a quantitative science - to predict the future
and then test it to confirm that what was predicted is correct ! 

We learn the Laws in physics,  because they are general and can be applied in 
thousands of ways to solve any type of problem. In order to solve a problem one
has to recognize the essence of the situation. Again it is the fact that if one
does not recognize what is to be determined that causes difficulty (as it did in
the thought problems.) The solution to this difficulty is the same, ask yourself:
"what is it that  the problem is looking for?" " What is given?"  "How are the 
variables related?" Then reread the statement of the problem. Finally, one will
come to a realization of what the problem is trying to find. In each of these 
problems types, one must take the initiative to try something. 

One mnemonic which has helped previous students is to organize the problem 
according to a prescribed method called "GURU CALIFORNIA". There are six steps:
G U R U  C A. 

G means to write down a symbol and value for each of the GIVENS. Note that some
of the givens may have to be found in the text. For example: the value of g 
(the acceleration due to the force of gravity. ) 

U means to state a symbol and unit for the UNKNOWN. 

R means to find a RELATIONSHIP between the givens and unknown. 

U means to use the units of the givens and determine if that is the proper UNIT
of the answer.

C means to rearrange the equation for the unknown and perform the CALCULATIONS. 

A means to state the ANSWER along with its symbol. 

One can use GURU ROAR for thought problems and GURU CA for quantitative problems.
This difference arises because when solving thought problems one is not normally 
interested in determining units and making an actual calculation.  Instead one 
will be rereading the statement of the problem and trying to apply a physical 
principle (LAW) to solve it. Thus ROAR means Read Over and Apply Reason. In 
thought problems one might have to ROAR several times, that may also be the case
with quantitative problems in odrer to understand what is to be solved.