I. Necessary Textual Descriptions
The purpose of the necessary explanations is to explain the physical process and the basis for
answering questions. What should we say when answering questions? We should consider the following
1. Explain the research object (individual or system, especially the problem solved by the combination
of holistic method and isolation method, we must pay attention to the transfer and transformation of
the research object);
2. Draw force analysis diagram, circuit diagram, optical path diagram or schematic diagram of motion
3. Explain the physical meaning of the letters.
4. Describe the specified positive direction and zero potential point (surface);
5. Explain the implicit and critical conditions in the title.
6. Describe the basis, name and corresponding physical process or state of the equations.
7. Explain the physical meaning of the results (sometimes need to be discussed and analyzed).
1. The equation written out (which is the basis of grading) must be the prototype formula. It can not
be replaced by the result of deformation. For example, when a charged particle moves in a magnetic
field, it should have qvB=m instead of the result of deformation R=.
2. Express the equation in letters, do not use equations mixed with numbers, and do not set equations.
3. To solve the problem simultaneously with the original equations, do not use the continuous equation,
and constantly "continue" into some content;
4. There are many equations. We should arrange them by fractions (score by steps). We should not write
them together. It is better to number them.
3. Necessary calculating process and definite results
1. In calculus, literal operations are usually carried out first, and the calculation formula of the
results is derived from the listed equations. Finally, the data are substituted and the results are
2. Data should be written by scientific notation.
3. The number of valid digits of the calculation results should be determined according to the
intention of the question. Two or three digits should be selected. If there are special requirements,
the digits should be selected according to the requirements.
4. The result of calculation is a unit of data, and it is better not to use irrational number or
fraction as the result of calculation (the coefficient of literal form can be used), it is not a unit
of alphabetic symbols.
Fourth, there is a particular way to use mathematics in solving problems.
1. "Substitute data" and the specific process of solving the equation can not be written out.
2. The geometric relations involved need only to write out the judgment results, but not to prove them.
3. The text expression of the important intermediate conclusion should be written out.
4. If there are many solutions to the equation, they should be written out, and then, through
discussion, they should be discarded.
5. When multiplying numbers, do not use "..." to connect them, but use "*" to connect them; when
dividing, do not use "" to apply "/".
5. Standardization of the use of various alphabetic symbols
1. Letter symbols should be clearly written and standardized, avoid scribbled handwriting. When marking
papers, it is not uncommon to deduct marks for "v, r, _", for "M, m" or "L, l", for "G" in cursive
form, for "a", for the Greek letters "rho, mu, beta, _" in stroke order or in incorrect shape.
2. Respect the symbols given by the title. If the title gives a radius of r, you will be wrong if you
write it as R.
3. A letter can only be used to represent a physical quantity in a topic, so that it can not be used
more than one letter; a physical quantity can not have multiple symbols in the same topic, so as to
4. Respect customary usage, such as pulling force with F, friction with f, markers will understand at a
glance, if used in the opposite way will bring misunderstanding;
5. Corner markers should be located in the lower right corner, much smaller than the letter itself.
Corner markers should also be selected carefully, such as the speed through point A using vA is better
than using v1, through a certain point of speed, according to the time sequence of the first use of v1,
the second use of V2 is very clear, if inverted, it will inevitably lead to misunderstanding;
6. Symbols of units of physical quantities originate from units of names, which should be capitalized
by a single letter, such as Coulomb C and Henry H. Units consisting of two letters are usually
capitalized at the front and lowercase at the back, such as Hz and Wb.
6. Disciplinary language should be standardized with disciplinary characteristics
7. Drawing graphics and images clearly and accurately
1. We must draw with pencils (easy to modify), compasses, rulers and triangles, and oppose freehand
drawing at will.
2. When drawing function images, we should draw the origin of coordinates and arrows on coordinate
axes, and mark the symbols of physical quantities, units and data on coordinate axes.
3. Graphics and lines should be clear and accurate, and the virtual and real parts of lines should be
distinct and different.