Chapter vi

I. Lens

Convex lens: it can condense light.

Concave lens: it has divergent effect on light.

Focus: the light parallel to the main optical axis passes through the convex lens and converges at point F, which is called the focus of the convex lens.

Focal length: The distance from the focal point to the optical center of the convex lens is called focal length.

The smaller the focal length of the lens, the more obvious the convergence (or divergence) effect.

2. The imaging law of convex lens.

Attribute of object distance image

Stand upright or upside down to enlarge or reduce a virtual image or a real image.

U & GT2F2 & GTV> Inverted Restore Real Image

U=2f v=2f inverted image.

2f>u>f v & gt2f Inverted Enlarge Real Image

U<f is enlarging the virtual image.

Three. Ordinary lens

1. Slide projector and projector

Imaging characteristics: When an object is between one focal length and two focal lengths of a convex lens, it becomes an inverted magnified real image.

Note: Slides should be placed upside down.

2. camera

Imaging object point: the object is out of the double focal length of the convex lens and inverted and reduced.

magnifier

Imaging characteristics: the object is in a vertical magnified virtual image within a focal length of the convex lens. The object is on the same side as the image.

Four. eye

From the imaging point of view, the human eye can be simplified as a convex lens and a screen.

Apparent distance: The image formed by an object at a distance of 25cm from the eyes is the clearest, so the distance of 25cm is called the apparent distance of normal eyes.

Myopia: The apparent distance is less than 25cm, and it can be corrected with concave lens.

Hyperopia: the apparent distance is greater than 25cm, and can be corrected by wearing a convex lens.

Glasses degree = 1/f× 100 (f must be in m). )

Chapter VII

I. Basic concepts:

1. Force is the action of one object on another. The forces between objects are mutual.

2. the symbol of force: F.

Unit of force: Newton; ordinary

3. The function of force: it can change the motion state of the object; Can change the shape of an object.

4. Dynamometer: dynamometer. (Spring dynamometer used in laboratory)

5. The three elements of force: the size, direction and action point of force.

The method of representing all three elements of force with line segments with arrows is called force diagram.

Two. gravity

1. The force that an object near the ground receives due to the gravity of the earth is called gravity.

Force object: the earth.

2. Gravity direction: vertical downward.

The gravity of an object is directly proportional to its mass.

G = mgg is 9.8N/kg, that is to say, the gravity of 1kg is 9.8N. ..

Three. rub

1. The force generated in the process of sliding friction is called sliding friction.

2. Factors of sliding friction: pressure; Roughness of contact surface.

3. Direction of sliding friction: opposite to the direction of motion of the object.

4. The method of increasing friction:

Increase the pressure; Roughening the contact surface;

Ways to reduce friction:

Relieve stress; Smooth the contact surface.

4. Two-force synthesis on the same line.

Same direction: F=F 1+F2.

Opposite direction: f = f1-F2 (f1> F2)

Verb (abbreviation for verb) is the balance of two forces.

1. An object is in a state of static or uniform linear motion, which is called balance. The force acting on a balanced object is called a balanced force.

2. If only two forces of an object are in equilibrium, it is called two-force equilibrium.

3. Conditions for the balance of two forces: If two forces acting on the same object are equal in magnitude and opposite in direction and act on the same straight line, we say that the two forces are in balance with each other.

When a balancing force is applied, the resultant force on the object is zero. Under the action of balancing force, the motion state of the object remains unchanged.

6. Newton's first law

1. When no external force acts on all objects, they always keep moving in a straight line at a uniform speed or at rest. This law is called Newton's first law, also known as the law of inertia.

2. The invariability of the moving state of an object is called inertia.

Chapter VIII

I. Stress

1. The force acting vertically on the surface of an object is called pressure.

2. The function of pressure: deform the object.

3. Influencing factors of pressure effect: the magnitude of pressure; The size of the stress zone.

4. Pressure direction: downward perpendicular to the contact surface.

Two. pressure

1. Meaning: a physical quantity indicating the influence of pressure.

2. Definition: The pressure acting on the unit area of an object is called pressure.

3. Formula: p = f/s; (Pressure = pressure/stressed area)

4. Unit: Pascal. protactinium

1pa = 1n/m2, which means that the pressure per square meter is 1n.

5. Ways to increase pressure:

Constant pressure reduces the stress area;

The stress area is fixed and the pressure increases.

6. Ways to reduce stress:

When the pressure is constant, the stress area increases;

The stress area is fixed, so the pressure is reduced.

Three. Internal pressure of liquid

1. Causes of internal pressure of liquid: liquid is subjected to gravity and has fluidity.

2. The law of liquid internal pressure:

(1) There is pressure in all directions in the liquid;

(2) At the same depth in a liquid, the pressure of the liquid is equal in all directions;

(3) The internal pressure of liquid increases with the increase of depth;

(4) The pressure inside the liquid is related to the density of the liquid.

3. Calculation formula of liquid internal pressure: p =

4. Communicator: A container with an open top and a connected bottom is called a communicator.

Features of the communication device: If there is only one liquid in the communication device, when the liquid is still, the liquid level in each container of the communication device is always flat.

Application of communicator: sewer return pipe; Water tower water supply system; Water level gauge; Automatic drinking fountain for livestock, etc.

Four. atmospheric pressure

1. There is pressure in all directions in the air, and this pressure is called atmospheric pressure.

2. A famous experiment to prove the existence of atmospheric pressure: the Madeborg Hemisphere Experiment;

Experiment of measuring atmospheric pressure: Torricelli experiment.

3. 1 standard atmospheric pressure = = 760mmhg (generation pressure) =1.01×105pa.

4. Factors affecting atmospheric pressure

① Atmospheric pressure decreases with the increase of height; (Within 2000m above sea level, the atmospheric pressure will drop by about 1 33pa (1mmHg) for every increase of12m.

(2) Under the condition of constant temperature, the volume of a certain mass of gas decreases, the pressure increases, the volume increases and the pressure decreases.

③ Atmospheric pressure is also related to weather, temperature and other conditions.

5. The application of atmospheric pressure:

Piston pump; Diesel engine driven centrifugal water pump

mathematics

There is no outline, and there are good review methods that can be recommended to you.

Study hard.

6 o'clock: You are still sleeping, but your body is awake and your endocrine function is active. If you get up at this time, don't worry, you'd better slow down.

8 o'clock: Cardiovascular and cerebrovascular diseases are easy to attack, and yoga is best postponed until 1 1. You can have breakfast at this time, but it is not suitable for taking homeopathic medicine.

9: 00: The last two hours are the best time to see the dentist, with the least pain and terror.

10: Suitable for attending official negotiations, completing various teaching tasks and passing the exam.

1 1: If you really want to eat cream cake, you'd better eat it now, not after lunch, because fat will be converted into energy instead of stored in the abdomen and thighs.

13: in the office, the staff yawned: at school, children are not smart. The best time for lunch break.

14 points: the body has the smallest electrostatic charge and is suitable for combing hair.

16: The body needs exercise, such as running, jumping and swimming. If you have to sit and work, you should also stand up for a walk and do squats, which is conducive to maintaining your work energy.

17: Relax time and play musical instruments. Your hands are the most flexible at this time.

18 o'clock: the best time to eat, but in moderation. At this time, excess heat will be converted into fat, not energy.

19: Take care of the skin. A nutritious mask will bring benefits. It is also best to take medicine and absorb it.

20 points: the pursuit of beauty is the strongest, and the inner world is the richest. Read picture books, read books and try on new clothes.

2 1 point: body temperature drops and metabolism slows down, so don't eat at this time. At this time, you will be particularly unbearable loneliness.

22 o'clock: Your liver doesn't want you to drink. Alcohol can also affect sleep and even the mood the next day. Smoking is also the most harmful to health at this time.

Point 23: Fantasy-bright prospects, lofty ideals and brand-new ideas. Usually these things are difficult to pass in real life.

24 o'clock: Until the morning-slow response, no firm purpose. If you don't sleep, you are most likely to be afraid and depressed. So, you'd better sleep!

1. The best time to fall asleep: 22: 00-23: 00 at night.

2. The best time to get up: 5 am -6 am

3. The best time to use your brain: think carefully at 8 am.

10: 00 Energetic

2 pm, quick thinking

Memory is the worst at 8 pm.

4. The best time to drink water: drink a glass of water after getting up in the morning or before each meal 1 hour.

5. The best time for a walk: 45 minutes after a meal.

6. The best time for physical exercise: 10: 00 am.

65438+ 5 pm

7. The best time to take a bath: take a warm bath before going to bed at night.

8. The best time for beauty: use skin care products before going to bed at night.

9. The best time for drinking tea: 65438+ 0 hour after meals.

10. The best time to eat fruit: 65438+ 0 hour before meals.

First, the physiological adjustment before the exam.

Work and rest according to the usual schedule. If you can't sleep in the morning, you can get up early, exercise and have breakfast. Psychologists have a general understanding that the best memory time in a day is 5:00-7:00 am and 7:00-9:00 pm. Making full use of these two time periods to solve things that need to be memorized can get twice the result with half the effort. You must take a nap at noon, and it is advisable to take a nap for 30 minutes, so that your brain can rest and wake up quickly. In the afternoon, you should focus on doing exercises, and you can concentrate on doing sets of questions. Pay attention to the combination of arts and sciences when doing problems. By doing the questions, you can stabilize your mind and build your confidence. After such a period of training, I believe you won't feel strange when you come to the exam.

Second, the emotional adjustment of anxiety and irritability before the exam.

1, aerobic exercise.

If you can't sleep in the morning, you can jump rope, take a walk, kick shuttlecock, run, ride a bike and so on. No matter what exercise you do, you should hold your head high and look confident, so that you can get a good mood for the day. Aerobic exercise has a law, namely; The heart rate per minute after exercise is about 120.

2. Take a hot bath.

Conditional candidates had better take a hot bath before going to bed every night. First, it can eliminate fatigue, and second, people's bodies are immersed in warm water, which is the most relaxed state, with a feeling of safety and warmth, which can purify the mind and is more conducive to sleep and study the next day.

3. Listen to music properly.

If you feel tired and can't remember anything, you might as well listen to classical music. For example: guqin music, guzheng music, dulcimer music, etc. Melodious, soothing and ethereal music can stabilize the mood. It is better to listen to music that you don't understand, because you don't need to remember it. It is best to listen during recess. But be careful not to listen to music while studying, especially not to listen to rock and pop songs.

4. Find someone to talk to and chat with.

Find optimistic people who can understand you and give you guidance at the same time (such as peers, teachers, parents, etc.) ), tell your inner anxiety and irritability, reasonably vent your bad emotions and clean up your mind. Don't press it in your heart and you won't get vent, which will directly affect the results of the senior high school entrance examination.

The first learning is when the memory is the strongest, that is, when the memory is integrated for 24 hours;

The second review is a week later;

The third revision is three months later;

The fourth revision was made six months later.

First of all, we should make a good study plan. We should make good use of our study time every day, every hour and every moment. Usually students should form this habit and make a general arrangement for the day's study every morning. After school, the decision will be supplemented and revised according to the teacher's arrangement. When to preview, when to review homework, when to read extracurricular books and so on. , and completed one by one on time. Generally speaking, the air is fresh, the environment is quiet and energetic in the morning. At this time, it is best to read or recite the text. Listen attentively to the teacher in the morning; I am very tired in the afternoon. We should mainly review old lessons or do some hands-on exercises; At night, there is little external interference, and attention is easy to concentrate. At this time, you should hurry to do your homework or write a composition. If we insist on doing this, students will form a good habit of using time scientifically.

Second, we should arrange the time for self-study classes. How to arrange the self-study class? Many schools regard completing homework as the only task of self-study, and almost all the self-study time is spent on doing homework. This arrangement is not appropriate. Because rushing to do homework before really understanding what you have learned is not only slow, a waste of time, but also prone to mistakes. Therefore, students should arrange some time to review what they have learned before doing their homework. As the saying goes, "sharpening a knife does not mistake a woodcutter". If you have a thorough understanding of knowledge and an open mind, you will do your homework quickly and well. In addition, after finishing your homework, you should arrange some time to preview, understand the content of the new lesson to be learned, and make clear the key points and difficulties, so as to listen to the lectures in a targeted manner and improve the learning efficiency.

When arranging self-study classes, we should also pay attention to the intersection of arts and sciences, and combine oral English with practical work, instead of learning the same subject at one go or reciting exercises for a long time, which will easily make people tired and reduce the utilization rate of time.

Third, learn to firmly grasp today. In order to make full use of time, students should learn the trick of "firmly grasping today". Many students have the habit of putting off today's work until tomorrow, which is very bad. You know, if you want to win time, you must seize every minute and don't let time pass in the blank. Tomorrow hasn't come yet, yesterday has passed, and only today has the initiative. Give up today, lose tomorrow, and you will accomplish nothing. So I hope that students will make good arrangements and cherish every minute from today.

For learning, it is particularly important to arrange the review time of the college entrance examination in the past year as a whole, arrange the daily time reasonably and improve the review effect to the maximum efficiency. Candidates can refer to the following daily study plan.

6: 00 a.m.-8: 00 a.m.: A day's work lies in the morning. For the average person, fatigue has been eliminated, the mind is clearest and the physical strength is abundant, which is the golden time for learning. You can arrange a comprehensive review of your lessons.

8: 00 am-9: 00 am: According to the test results, people's endurance is at its best at this time, which is a good opportunity to accept various "tests". Can arrange difficult content.

9: 00 am-11:Experiments show that the short-term memory effect during this period is very good. It can get twice the result with half the effort in "grabbing records" and the content to be assessed.

Noon 13-14: People are prone to fatigue after eating, especially in summer. Rest and adjust, save your strength and fight again. It's best to have a rest and listen to light music. But the lunch break should not be too long.

15 pm-16 pm: after adjustment, I feel refreshed. Experiments show that the long-term memory effect at this time is very good. Things that need "permanent memory" can be arranged reasonably.

17 in the afternoon-18 in the afternoon: Experiments show that this is a good time to complete complex calculations and compare brain-consuming tasks. This time is suitable for complicated calculations and hard work.

After dinner: it should be arranged according to everyone's situation. It can be divided into two or three sections, and Chinese, mathematics, foreign languages and other arts and sciences are arranged alternately; It can also be arranged alternately.

The following is the daily schedule of an excellent candidate in the college entrance examination for your reference:

Get up at 6 o'clock every day, review English at 6: 30-7: 30, review math at 7: 40-9: 40, and arrange flexibly at 9: 50-1:50; Lunch break at noon; Review chemistry from 2: 00 pm to 4: 00 pm, and review physics at 4: 10-6: 10 pm; Review Chinese for 2 hours in the evening; Maneuver the rest of the time. In the review of each course, we should read more textbooks or do more exercises according to the different contents of different stages and master them well.

Any attempt to change the biological clock will leave the body with inexplicable diseases, and it will be too late to regret it after twenty or thirty years.

1.9- 1 1 pm is the time for the immune system (lymph) to detoxify. During this time, you should be quiet or listen to music.

2. From 1 1 in the evening to 1 in the morning, liver detoxification needs to be carried out while sleeping (so, you should fall asleep at 1 1 at the latest: ()

Third, 65438+ 0-3 am, the detoxification of gallbladder needs to be carried out while sleeping.

Fourth, at 3-5 am, the lungs are detoxified. The person who coughs the most during this time, because the detoxification action has reached the lungs; Do not use cough medicine, so as not to inhibit the elimination of waste. 4 o'clock in the morning is the period of spinal hematopoiesis, so you must fall asleep.

5. At 5-7 in the morning, the large intestine is detoxified, and you should go to the toilet to defecate (it seems that the habit maintained since childhood is really beneficial).

6. At 7-9 am, when the small intestine absorbs a lot of nutrients, it is time to eat breakfast. It is best for patients to eat early, before 6: 30, and it is best for health people before 7: 30. People who don't eat breakfast should change their habits, even eating until nine o'clock or 10 is better than not eating at all.