Physics - one of the most difficult school objects. At the same time, the school student solving problems of physics at the good level without any problem can pass all Unified State Examination and enter to technical college. The solution of physical tasks is especially useful also that forms the rational and logical thinking necessary for the student of higher education institution in which (as well as in all technical educational institutions) the physics will be a specialist subject.
It is required to you
- Calculator, report of the basic physical formulas
Instruction
1. Before the solution of a task it is necessary to fill out the section ""Is given"" in which it is necessary to present short record of a task. Here it is necessary to specify all physical quantities which values appear in a task. Further it is necessary to fill out the section ""Find"" in which it is required to write down all sizes, necessary for the decision.
2. The following step is drawing up the drawing to a task. The correctness of implementation of the decision also depends on correctness of the drawing. The wrong drawing by all means will lead you to the incorrect answer. For drawing up the drawing at first sort out what it is in a task about. Represent at first all bodies and objects participating in physical process. It can be material points, the inclined planes, various partitions, blocks and suspensions. The last stage by drawing up the correct drawing is connection of these objects among themselves (coupling of material points, their binding to blocks, levers or suspensions).
3. After you make the drawing, it should be noted all forces operating on material points. Do not forget also that several forces in succession can affect a body. As a result at you has to the drawing for the decision will turn out, similar to presented on the picture.
4. Newton's laws - the most important tool allowing to solve problems of physics on force. Most often it is necessary to use the second and third laws of Newton. Under the second law the acceleration received by a body to force in direct ratio applied to it and in inverse proportion to its weight. In an algebraic form it registers as F=m*a where F - equally effective (sum) of all forces, acting on a body, m - its weight, an - acceleration. The third law of Newton says that force of action is equal to counteraction force on the module and are identical by the nature. It registers as | F12 |= |F21| where the left member of equation shows force with which the first body affects the second, and right - action of the second body in the first.
5. Further we write down the general equation to a task where we in one member of equation write down all forces, acting on a body, and in the second - equally effective all forces under the second law of Newton. General view of the equation: F1+F2+F3+...+FN=m*a. What is very important, we place signs in the equation taking into account the drawing.
6. Further we substitute all known values in the received equation and we find necessary sizes. So we can solve any problem of physics on force, the main thing not to be mistaken in calculations and to truly write down the answer.