Swollen to do physics problems, the first year of high school children to learn how to learn

To understand the topic, you must first grasp the key words, such as "regardless of rope weight", "regardless of air resistance", "smooth" is no friction, uniform acceleration, uniform deceleration, acceleration with reduced acceleration Mind to be clear and understand, and then follow the feeling to do it, I do this, I understand all the physical things, and then I will do the question, the question is changed soup, not the medicine, no matter how deformed is the principle, so the key is to understand Physics, I also took the first place in the school? If you understand the principle, you will do it, really.

Learn Physics Methods: 1. Listen to the teacher's lectures;

2. After class, I am watching the content that the teacher has said;

3 questions sea tactics.

First understand the knowledge in the textbook, the topic is just the process of applying the knowledge, and the topic is always the same.

To review the question first, you need to chew the words, clarify the physical situation and process of the problem, and then correspond to the knowledge, list the equations according to the relevant laws, and finally solve them.

To learn physics, you must first cultivate interest, and in your free time, you can understand the history of physics development, and look at popular science knowledge, which is helpful for the understanding of knowledge. Don't just do the questions, analyze and understand the meaning of the formula, and ask yourself why.

With the starting point of the person as the coordinate origin, the upward is the y-axis, and the ground is the x-axis to establish a Cartesian coordinate system, the person is 3 meters away from the grid, and the net is 2m high, so the coordinates (3, 2) at the top of the net The total length of the field is 18m, and the half-field length is 18 2 = 9m

Then, the distance between the person and the opponent's bottom line is: 3+9=12mThe law of flat throwing motion: t= (2 h g).

Displacement of horizontal motion s=vt

When the smash is just over the net (without touching the net):

h1=t1=√(2△h1/g)=√(2* s

So, v1=s1 t1=3 [( 10) 10]=3 10 when the smash flies exactly to the baseline (out of bounds):

h2=t2=√(2△h2/g)=√(2* s

So, v2=s2 t2=12 [( 2 2)]=12 2 so, vo (3 10, 12 2].

2) It's more complicated, I'll attach you a picture separately.

The height of the shot should be, right?

1) When the minimum speed v1 is just over the net, according to the formula h=t1= (2*

v1=3/t1=6√5m/s

At the maximum speed v2, it just reaches the boundary.

t2=√（2*

v2=12/t2=12√2m/s

So 12 2m s v> 5 10s

2) h At the maximum allowable height, the shot is exactly past the net and the border.

Let the height h, velocity v, pass through the net and the boundary time t1 and t2 horizontal motion respectively: t1:t2=3:12=1:4

So the height drop ratio is 1:16

h=1:16 h=

So when H, no matter how high the horizontal muzzle velocity of the ball is, it will touch the net or cross the bounds.

There is a problem with the question, how can there be a shot out of a place 3m high off the grid and fly over 3m at a height of the same as the same said.

I'm now a sophomore in high school, and in terms of theory, I think I'm still a little accomplished (brag ha!). ）。For physics, it's actually about understanding the basics, and I think the basics are too bad in the textbooks (those experts really don't know what to think!).

You can buy a teaching aid.,Like what's 53 (5 years and 3 years of that.,N people in the class gnaw),Or I think it's easy to use the queen male school case (no advertising.,It's really easy to use),There will be those basic knowledge in front.,Take the first step when you understand it.。 Then there are the formulas, and it's best to deduce them yourself, but the formulas are all derived from the basics.

For example, Newton's second law learned in the first year of high school: the magnitude of the acceleration of an object is directly proportional to the force exerted on the object, inversely proportional to the mass of the object, and the direction of acceleration is the same as the direction of the combined external force. f=ma is derived.

And then there's the title. If you do the topic, you should actually be able to connect with life and be able to imagine. Just like the problem of force, there is force everywhere in life, walking is powered by friction, and the acceleration of the car is also powered by the traction of the start, so that it is linked to life, and basically compulsory (gravity is also available) can be solved.

Then it is necessary to use the law of conservation of energy to solve the problem, analyze the energy loss of the object, the energy carried by itself, and the energy of the original state, which can be done.

Then there is no need to do many questions in physics, and there are sea tactics for questions. Just do some examples. After a long time, do it again, familiarize yourself with the formulas and theorems, and slowly there will be qualitative changes. That's the truth about the old and the new.

A big feature of high school physics problems is that they are modeled. If you are careful, you will find that many problems can be grouped into a model, or a combination of several models, such as flat throwing, magnetic focusing, circumferential centripetal force, guide rail, and so on. In view of the above facts, I learned it like this:

1. Lay a good foundation, find a book with a round of materials, the kind with explanations, I think the books on the market are almost the same, and wear all the knowledge points.

2. Special training, according to a set of papers or 53, to make breakthroughs in each content.

3. Summarize and summarize, often classify the problems you have done, compare the similarity of their methods, refine the model, and summarize some routines by yourself.

Break down a problem into many small problems, a complex movement is composed of simple small movements, high school physics is still very simple ......

Mainly depends on what type. For calculation questions, whether you have to write the formula first, if you don't understand the question, write all the relevant formulas.

In the analysis, most of the mechanics directors are orthogonally decomposed, optimistic about the angle, and turn the mechanics into equations.

Multiple-choice questions should be easy first. Put down the problem, and come back to it after completing the big problem.

As can be seen from the question, the object begins to move with uniform acceleration x= i.e. 4 a=2 v=at=2 2=4

The force analysis of the object shows that the object is affected by gravity g, tensile force f, support force n, and friction force f, and in the vertical direction: n=g-fsin53°=

In the horizontal direction, there are: f f, f, f, 53°, f=3-f, f, f'Namely'

x'=8

General practice. First force analysis.

t=, the displacement s of the object is , and the force is found in the known motion.

Remove the constant force f, and then analyze the force to find a

Then find the motion.

This is the typical application of Newton's second law.

This topic should be done by analyzing the whole process clearly, otherwise it will not be easy to start.

First of all, the AB rod does a variable speed movement upwards under the action of constant force F, and the AB rod has a certain speed, which produces an induced current, so there is an ampere force, judging by Lenz's law, the ampere force must be oblique downward, with the increase of speed, the ampere force is also increasing, until a certain moment The sum of the components of the ampere force and gravity along the oblique down is balanced with F, the speed no longer increases, and the ampere force does not increase, which is the maximum value of the speed and the speed stability mentioned in the question. After removing F, AB will do a deceleration movement, the ampere force continues to decrease with the high eggplant, until the speed is 0, the ampere force is also 0, at this time AB is also affected by gravity, it will inevitably decline, the speed begins to increase again, and the induced current is generated again, pay attention to the change in the direction of the ampere force, the direction is oblique upward, until the magnitude of the ampere force and gravity are balanced along the oblique component, and the velocity reaches the maximum again, the speed has been given in the question and the upward velocity is the same, and then the AB force balances the uniform motion to the starting point.

This process is analyzed, and the question is easy to solve.

The ampere force and gravity balance along the slope of the glide process: f=bil=mgsin (1)i=e r=blv r(2).

From (1) and (2), the rising process of velocity v=(rmgsin) b 2l 2 can be solved, and the sum of the components of the ampere force and gravity along the slope is balanced with the constant force f.

f=mgsinθ+f

And because the maximum speed of ascent and the maximum speed of descent are equal, then the ampere force is also equal.

So f=mgsin

then f=2mgsin

Persistence is required. Clarify the basic concepts and familiarize yourself with where they come from and how they relate to each other.

It is necessary to do some questions independently, with quality and quantity. There should be a certain number of questions, not too many, not too few, but also a certain quality, that is, a certain degree of difficulty. Anyone who learns mathematics, physics and chemistry will not be able to learn well without going through this level.

Solving problems independently, sometimes slowly, sometimes detours, sometimes even unable to solve them, but these are normal and the only way for any beginner to succeed.

It is necessary to be clear about the physical process, and there is inevitably a hidden danger of solving the problem if the physical process is not clear. Regardless of the difficulty of the topic, you should draw as much as possible, some sketches are sufficient, and some should be precise to show the geometric relationship. Drawing can transform abstract thinking into figurative thinking and grasp physical processes more precisely.

With graphs, state analysis is fixed, dead, and intermittent, while dynamic analysis is alive and continuous.

Study materials should be well preserved, classified, and marked. The study materials are categorized into practice questions, test papers, lab reports, and more. Marking means, for example, for practice questions, that the general questions are not marked, and the good questions, valuable questions, and error-prone questions are marked differently for future reading, and marking can save a lot of time.

It is necessary to attach importance to the knowledge structure and systematically grasp the knowledge structure, so that the scattered knowledge can be systematized. It is as large as the knowledge structure of the whole physics, as small as the knowledge structure of mechanics, and even down to the chapters, such as the knowledge structure of statics, and so on.

You're right, you don't have an interest in learning, you really can't learn a course well, I have also encountered this situation of children, there are a lot of such children, I can only give you a few suggestions:

1.At present, the most important thing is to cultivate interest in learning, do some simple questions first, do the right questions to encourage him, or you are surprised by him to do these topics, so that he has a sense of achievement, and at the same time point out the problems he did wrong, encourage him, help him complete, don't do too many problems at a time, one or two can be. Interest needs to be cultivated slowly, not overnight.

2.It is very important to listen to the class, guide him, let him talk about the content of the teacher's class, and at the same time you keep asking questions to make him think, and the questions you ask are the questions he should ask. That's all I have to say about time.

The best way to learn physics is (((pre-class preview))) actually 100 questions after class, not as good as 10 minutes before class, before the class has already understood what the teacher said, then it sounds much simpler, you must know that each child's reaction is different, especially physics and mathematics, the teaching speed of high school is much faster than that of junior high school, these two subjects if you react slowly, you can't keep up, physics is a pure comprehension subject, you have to memorize very little, the brain can't get around, When you want to go to a knowledge point, the next knowledge point has already begun, so are you still busy, students will hate this subject when they are struggling in class, high school physics as long as you understand that it is actually the least time-consuming one, the whole high school is mechanics, optics, electromagnetism, a few difficult problems can include all the knowledge points, but girls learn physics more difficult than boys, and many girls are difficult to understand even the content of textbooks in the first year of high school. You still accompany your child to preview every night, it is best to preview each subject, as long as you do it, it is not easy to say that the undergraduate is not good, if you go online, even if you only have half a day of class in the third year of high school, you can rely on it.

It is indeed difficult for girls to learn physics. But as long as you work hard, you can learn well, or even learn well! The first is to learn the basics, the second is to do more hands-on, connect with reality, and the third is to do more questions. The most important thing is to think about it and understand it a lot. Hope it helps.

The main reason is that I didn't figure out the basic concepts, as long as the concepts are clear, then I can do the right amount of questions.

I am now a high school physics teacher, and the learning of high school physics is actually a very systematic thing. The detailed content can be added, and we can be detailed**.

Isn't high school physics all about formulas? . .

Answer: Resistance B 50mA

In the circuit, R B and the multi-meter are connected in series and then in parallel with R A, and the current of R B is measured by the meter.

The ammeter range is 0-100mA, and when the pointer is on the ** scale, the current is 50mA

If you draw the circuit diagram, you can see that it is blocked without passing through the resistance of A 90mA.

The most intuitive way to solve this kind of pursuit problem is to make a schematic diagram and find out the equivalent relationship of displacement.

1) b is a uniform acceleration linear motion with an initial velocity of 12m s, and a is a uniform acceleration linear motion at the initial position of 0m s to 5m.

That is to say, a is a linear motion with uniform acceleration at a certain speed at 5m. And B catches up with A, that is, the total displacement of B is equal to the total displacement of A.

2) Based on (1), the time has been calculated, and the displacement of b is calculated with time and acceleration, and then subtracted by 5m is the displacement of a.