General Practice in Solving Physics Problems for IIT JEE
Using a system of fundamental concepts makes it possible to formulate the most important definition of a theoretical physical problem as a physical phenomenon in which some of the relationships and quantities are unknown.
To solve physics problem means to establish the unknown relationships and determine the sought physical quantities.
This definition is extremely important methodologically. If a physics problem reflects a physical phenomenon (or collection of phenomena), it is necessary not only to have specific knowledge about this phenomenon but also to know how to analyze any physical phenomenon by applying generalized knowledge. This analysis begins with the choice and analysis of a physical system and ends with the construction of a closed system of equations by the application of the appropriate physical laws. In view of this the solution process breaks down into three stages:
1. The physical Solution (which ends with the construction of the closed system of equations)
2. The mathematical (designed to obtain a solution in general and numerical forms),
3. Analysis of this solution.
This, naturally, requires building a system of methods for solving physics problems as a system of general guidelines for each of the three stages.
It is believed that no one method for solving all physics problems exists. This may be true. I believe, however, that there exists a general approach (system of methods) to the solution of any physics problem.
It is often said, in fact, that if you want to learn to solve physics problems, you must solve them independently. This is true, of course. But if the person solving the problem is not taught the general ways (methods) of problem solving, he will use the torturous trial-and-error method. This makes it necessary to have a system of general methods for carrying out all the stages in the solution of an arbitrary physics problem, a system that serves as a set of rules for independent work. Hence, the system of general methods must have the following properties:
(a) It must be universal, that is, applicable to the solution of any problem in the general physics course; and
(b) It must encompass all the stages of solution.
After analysing the ways in which each stage in problem solving needs to be carried out, we suggest the following system of general methods:
(1) Analysis of the physical content of a problem;
(2) Application of a physical law;
(3) General-particular methods;
(4) Simplification and complication method; and estimate;
(5) Analysis of the solution; and
(6) Referring back to Problem statement before choosing the answer.
It must be noted that no method taken alone is universal. Each has meaning and manifests itself fully only within the system of methods, and this system does not always automatically guarantee solution of the problem. Sometimes a problem can be solved without applying any method that is by intuition. But solutions will be obtained much faster and more often if one acts in accordance with these methods. In short, the system of general methods is not a dogma but a guide to independent work in solving a physics problem, not an instruction but a system of intelligent advice.