From natural philosophy in Aristotle's time to classical mechanics in Newton's time, and then to relativity and quantum mechanics in modern physics, all these are tangible manifestations of physicists' scientific quality, scientific spirit and scientific thinking. With the development of science and technology and the progress of society, physics has penetrated into all fields of human life.
For example, just looking for the optical knowledge in the car has the following points: 1. The rearview mirror outside the driver's cab is a convex mirror. By using the divergent effect of the convex mirror on light and the characteristics of vertical, narrow and virtual image, the real object you see is smaller and the observation range is wider, thus ensuring driving safety. 2. The reflector in the car headlights is concave mirror, which is made by using the property that concave mirror can reflect the light from the light source at its focus into parallel light.
Car headlights is always equipped with glass lampshades with horizontal stripes and vertical stripes. Automobile headlights consist of a light bulb, a mirror and a glass cover in front of the lamp. According to the knowledge of lens and prism, car headlights glass cover is equivalent to the combination of lens and prism.
When driving at night, drivers should not only see the road ahead, but also see the fixers, road signs, forks and so on. The lens and prism refract the light, so the lampshade diffuses the light to the required direction according to the actual needs, so that the light illuminates the road in front of the car and the roadside scenery evenly and softly. At the same time, this astigmatism lampshade can slightly refract some light to illuminate road signs and milestones, thus ensuring driving safety.
4. After the car is fitted with brown glass, it is difficult for pedestrians to see the faces of people in the car clearly. The brown glass can reflect part of the light and absorb part, so the light penetrating into the car is very weak. In order to see the passenger's face clearly, it is necessary to reflect enough light from the face and transmit it to the outside of the glass.
Because the light inside the car is weak and there is not enough light to transmit, it is difficult to see the passenger's face clearly. Except for buses, the front windows of most cars are inclined. When the front window of the car is tilted, the image of the passenger in the car reflected by the glass is in front, and it is impossible for pedestrians on the road to appear in the air above, so that the image of the passenger in the car is separated from the pedestrians on the road, and the driver will not have an illusion.
The front window of a bus is much higher than that of a car. Even the vertically installed front window looks the same height as the window, and pedestrians on the road cannot appear at this height, so drivers will not confuse the image of passengers outside the window with pedestrians on the road. Another example is as follows: spiced tea eggs are very popular with people, especially when they are hot.
Careful people will find that when the eggs are just taken out of the boiling gravy, if they are eager to shell and eat them, it is inevitable to peel them off with the "meat". To solve this problem, there is a trick, that is, soak the eggs just out of the pot in cold water for a while, and then peel them, so that the eggshells can be peeled easily.
General substances (with a few exceptions) have the characteristics of thermal expansion and cold contraction. However, when different substances are heated or cooled, the speed and amplitude of expansion and contraction are different.
Generally speaking, substances with low density are easier to expand and contract than substances with high density, and substances with fast heat transfer are easier to expand and contract than substances with slow heat transfer. An egg consists of a hard shell, a soft protein and a yolk, and their expansion and contraction are different.
When the temperature changes slightly or slowly and evenly, nothing can be displayed; Once the temperature changes dramatically, the expansion and contraction speeds of eggshells and protein are inconsistent. When the boiled egg is immediately immersed in cold water, the temperature of the eggshell will decrease and shrink rapidly, while protein is still at its original temperature and does not shrink. At this time, a small part of protein will be squeezed into the short position of the egg by the eggshell.
Then, due to the decrease of temperature, protein gradually contracted. By this time, the contraction of the eggshell was already very slow, and protein was separated from the eggshell. Therefore, when peeling, the shell and the "meat" will not come off together. Physics in life comes from: Free paper net. It is very useful for us to understand this truth.
If all things that need to undergo great temperature changes are made of two different materials together, their thermal expansion performance must be considered when selecting materials, and the closer they are, the better. Reinforced concrete is widely used when engineers design houses and bridges. Because the expansion degree of steel bars and concrete is similar. Although the temperature is different in spring, summer, autumn and winter, it will not produce harmful forces, so reinforced concrete buildings are very strong.
In addition, some electrical components are made of two metals with very different thermal expansion characteristics. For example, the thermal expansion of copper sheet is greater than that of iron sheet, and the bimetal nailed together by copper sheet and iron sheet will bend due to different expansion degrees when heated under the same conditions.
Using this characteristic, many automatic control devices and instruments have been manufactured. There is a small bimetal in the "starter" of the fluorescent lamp, which can automatically expand and contract with the change of temperature, thus playing the role of automatically turning on the fluorescent lamp.
There are countless examples of this. Physics is a practical science, which is closely related to industrial and agricultural production and daily life. Physical laws themselves are generalizations and abstractions of natural phenomena.
When it comes to physics, some students find it difficult; When it comes to physical inquiry, some students feel unfathomable; Speaking of physicists, some students think they are not ordinary people. It is true that there are only a handful of physicists, but as long as you are diligent in observation, good at thinking and brave in practice and innovation, you will find that physics is around you.
As Marx said, "Science is experimental science, and science lies in arranging perceptual materials in a rational way". Physics is not only a discipline but also a science.
Physics exists around physicists. Galileo, an observant Italian physicist, took great interest in the swing of the copper chandelier hanging in the air in Pisa Cathedral when he was attending church. Later, after repeated observation and research, he invented the synchronization of the pendulum. America that dares to practice.
2. Write an 800-word treatise on "Physical phenomena in life". In fact, there are many simple physical knowledge hidden in seemingly ordinary phenomena in life.
Physics is all around us. As long as you observe and experience carefully, you will find that you have come to the colorful material world, where you will find a new starting point in life. For example, spiced tea eggs are very popular, especially when it is hot.
Careful people will find that when the eggs are just taken out of the boiling gravy, if they are eager to shell and eat them, it is inevitable to peel them off with the "meat". To solve this problem, there is a trick, that is, soak the eggs just out of the pot in cold water for a while, and then peel them, so that the eggshells can be peeled easily.
This is based on the property that materials expand when heated and contract when cooled. Different substances expand and contract at different speeds and amplitudes when heated or cooled.
Generally speaking, substances with low density are easier to expand and contract than substances with high density, and substances with fast heat transfer are easier to expand and contract than substances with slow heat transfer. An egg consists of a hard shell, a soft protein and a yolk, and their expansion and contraction are different.
When the temperature changes slightly or slowly and evenly, nothing can be displayed; Once the temperature changes dramatically, the expansion and contraction speeds of eggshells and protein are inconsistent. When the boiled egg is immediately immersed in cold water, the temperature of the eggshell will decrease and shrink rapidly, while protein is still at its original temperature and does not shrink. At this time, a small part of protein will be squeezed into the short position of the egg by the eggshell.
Then, due to the decrease of temperature, protein gradually contracted. By this time, the contraction of the eggshell was already very slow, and protein was separated from the eggshell. Therefore, when peeling, the shell and the "meat" will not come off together. It is very useful for us to understand this truth.
For example, when designing houses and bridges, reinforced concrete is widely used, because the expansion degree of reinforced concrete is similar to that of concrete, and it is not affected by temperature. Although the temperature is different in spring, summer, autumn and winter, it will not produce harmful forces, so the houses and bridges are very strong. In the colorful world, there are colorful physical phenomena. As long as we carefully observe the things around us and find their laws, we can use them for me.
3. Write an article of not less than 500 words with physics as the topic. Abstract: Physics is a natural subject with a long history.
With the development of science and technology and the progress of society, physics has penetrated into all fields of human life; Physics exists around physicists; Physics also exists around students; In learning, students should establish scientific consciousness, focus on the big picture, start with small things, experience observation, thinking, practice, innovation and other activities, gradually master scientific learning methods and train scientific thinking methods, and soon you will have the mind of a scientist, laying a solid foundation for your amazing development and beautiful life in the future. Keywords: Physics permeates all fields of human life. Physicists are surrounded by scientific consciousness, scientific learning methods and scientific thinking modes. As an important branch of natural science, physics not only plays an important role in promoting the progress of material civilization and deepening human understanding of nature, but also has an indispensable influence on the development of human thinking.
From natural philosophy in Aristotle's time to classical mechanics in Newton's time, and then to relativity and quantum mechanics in modern physics, all these are tangible manifestations of physicists' scientific quality, scientific spirit and scientific thinking. With the development of science and technology and the progress of society, physics has penetrated into all fields of human life.
For example, just looking for the optical knowledge in the car has the following points: 1. The rearview mirror outside the driver's cab is a convex mirror. By using the divergent effect of the convex mirror on light and the characteristics of vertical, narrow and virtual image, the real object you see is smaller and the observation range is wider, thus ensuring driving safety. 2. The reflector in the car headlights is concave mirror, which is made by using the property that concave mirror can reflect the light from the light source at its focus into parallel light.
Car headlights is always equipped with glass lampshades with horizontal stripes and vertical stripes. Automobile headlights consist of a light bulb, a mirror and a glass cover in front of the lamp. According to the knowledge of lens and prism, car headlights glass cover is equivalent to the combination of lens and prism.
When driving at night, drivers should not only see the road ahead, but also see the fixers, road signs, forks and so on. The lens and prism refract the light, so the lampshade diffuses the light to the required direction according to the actual needs, so that the light illuminates the road in front of the car and the roadside scenery evenly and softly. At the same time, this astigmatism lampshade can slightly refract some light to illuminate road signs and milestones, thus ensuring driving safety.
4. After the car is fitted with brown glass, it is difficult for pedestrians to see the faces of people in the car clearly. The brown glass can reflect part of the light and absorb part, so the light penetrating into the car is very weak. In order to see the passenger's face clearly, it is necessary to reflect enough light from the face and transmit it to the outside of the glass.
Because the light inside the car is weak and there is not enough light to transmit, it is difficult to see the passenger's face clearly. The front windows of most cars are inclined except buses. When the front window of the car is tilted, the image of the passenger in the car reflected by the glass is in front of us, but the pedestrians on the road can't appear in the air above, so that the image of the passenger in the car is separated from the pedestrians on the road, and the driver will not have an illusion.
The front window of a bus is much higher than that of a car. Even the vertically installed front window looks the same height as the window, and pedestrians on the road cannot appear at this height, so drivers will not confuse the image of passengers outside the window with pedestrians on the road. Another example is as follows: spiced tea eggs are very popular with people, especially when they are hot.
Careful people will find that when the eggs are just taken out of the boiling gravy, if they are eager to shell and eat them, it is inevitable to peel them off with the "meat". To solve this problem, there is a trick, that is, soak the eggs just out of the pot in cold water for a while, and then peel them, so that the eggshells can be peeled easily.
General substances (with a few exceptions) have the characteristics of thermal expansion and cold contraction. However, when different substances are heated or cooled, the speed and amplitude of expansion and contraction are different.
Generally speaking, substances with low density are easier to expand and contract than substances with high density, and substances with fast heat transfer are easier to expand and contract than substances with slow heat transfer. An egg consists of a hard shell, a soft protein and a yolk, and their expansion and contraction are different.
When the temperature changes slightly or slowly and evenly, nothing can be displayed; Once the temperature changes dramatically, the expansion and contraction speeds of eggshells and protein are inconsistent. When the boiled egg is immediately immersed in cold water, the temperature of the eggshell will decrease and shrink rapidly, while protein is still at its original temperature and does not shrink. At this time, a small part of protein will be squeezed into the short position of the egg by the eggshell.
Then, due to the decrease of temperature, protein gradually contracted. By this time, the contraction of the eggshell was already very slow, and protein was separated from the eggshell. Therefore, when peeling, the shell and the "meat" will not come off together. It is very useful for us to understand this truth.
If all things that need to undergo great temperature changes are made of two different materials together, their thermal expansion performance must be considered when selecting materials, and the closer they are, the better. Reinforced concrete is widely used when engineers design houses and bridges. Because the expansion degree of steel bars and concrete is similar. Although the temperature is different in spring, summer, autumn and winter, it will not produce harmful forces, so reinforced concrete buildings are very strong.
In addition, some electrical components are made of two metals with very different thermal expansion characteristics. For example, the thermal expansion of copper sheet is greater than that of iron sheet, and the bimetal nailed together by copper sheet and iron sheet will bend due to different expansion degrees when heated under the same conditions.
Using this characteristic, many automatic control devices and instruments have been manufactured. There is a small bimetal in the "starter" of the fluorescent lamp, which can automatically expand and contract with the change of temperature, thus playing the role of automatically turning on the fluorescent lamp.
There are countless examples of this. Physics is a practical science, which is closely related to industrial and agricultural production and daily life. Physical laws themselves are generalizations and abstractions of natural phenomena.
When it comes to physics, some students find it difficult; When it comes to physical inquiry, some students feel unfathomable; Speaking of physicists, some students think they are not ordinary people. It is true that only a few people become physicists, but.
4. Ask for an essay entitled "The Application of Physics in Life". Physics is a very interesting and useful natural science, and its research content is very extensive.
In fact, there are many physical phenomena around us in life. Why can planes fly in the sky? Why can thermos keep warm? Why can the motor rotate? Why can you see farther with a telescope? Why is there a halo around the sun that looks like a rainbow? Why are the sky and the sea blue? Why does porridge overflow when it is cooked? What does the hole in the pen do? Why do jiaozi or meatballs float when cooked? Why do glassware crack when it is hot or cold? How is boiling water cold? Why can't a tumbler fall? Why is the pen out of water? Why don't water skiers sink into the water? Is tug-of-war just a fight for strength? ……
When we master the necessary physical knowledge, we can not only explain these phenomena, but also use them to serve mankind.
The ever-changing physical phenomenon is like a mystery. When we have mastered the necessary physical knowledge and solved the mystery, we will realize that physical phenomena are very interesting. . cn/wlgshwl/
Go to this website, where there is a lot of content about "physics in life"
Give you a few more examples:
1, quartz clock hanging on the wall, when the battery runs out and stops, its second hand often stops at the position of "9" on the dial. This is because the second hand is most hindered by the large torque at the "9" position.
2. Sometimes, when tap water flows from the adjacent faucet, it occasionally makes bursts of noise. This is because the water pipe vibrates when the water rushes out of the tap.
3. When taking pictures in front of the TV screen, turn off the camera flash and indoor lighting to make the pictures clearer. Because the reflected light of the flash lamp and the illuminating lamp on the TV screen will interfere with the transmitted light of the TV picture.
At the same temperature, frozen pork thaws faster in water than in air. At the same temperature, hot nails cool faster in water than in air. A cup filled with boiling water cools faster when immersed in water than when immersed in air at the same temperature. All these phenomena show that water has better heat transfer performance than air,
When the pot is filled with cold water, the water droplets attached to the outer surface of the pot bottom can only be dried on the flame for a long time, and then they will boil. This is because the water droplets, the pot and the water in the pot keep heat conduction, and the temperature is similar. As long as the water in the pot is not boiled, the water droplets will not boil, but will evaporate on the flame and gradually dry up.
6. Distorted mirror, the farther people are from the mirror, the more distorted they are. Because the image in the mirror is formed by the reflection of the silver-plated surface behind the mirror, uneven silver-plated surface or uneven glass thickness will lead to aliasing. The farther away from the deformed mirror, the more the reflected light on the silver-plated surface deviates from the normal position according to the principle of light amplification, and the more deformed the mirror is.
7. There are several small holes communicating with the outside world on the side of the gas nozzle of the natural gas furnace, but natural gas will not be ejected from the side holes, but only from the nozzle. This is because the air velocity at the nozzle is high, and according to the principle of fluid mechanics, the air surface pressure is lower than the atmospheric pressure outside the side hole, so the natural gas will not be ejected from the side hole of the nozzle.
8. After blowing the balloon, hold the mouthpiece with your hand and then suddenly release it. The air in the balloon is ejected and the balloon moves due to recoil. You can see that the route of balloon movement is tortuous. There are two reasons: first, the thickness and tension of the inflated balloon are uneven everywhere, which makes the balloon contract unevenly and swing around when it is deflated, thus the movement direction changes constantly; Second, the shape of the balloon is constantly changing during the contraction, so the air velocity on the surface of the balloon is also constantly changing during the movement. According to the principle of fluid mechanics, the air pressure on the surface of the balloon is constantly changing, so the balloon swings and the direction of movement is also constantly changing.
9. When the ceiling fan rotates normally, the tension at the suspension point is smaller than when it does not rotate. The greater the rotational speed, the more the tension decreases. This is because when the ceiling fan rotates, the air has an upward reaction force on the ceiling fan blades. The greater the speed, the greater the reaction.
10, electric furnace "combustion" is the conversion of electric energy into internal energy. Without oxygen, it can only oxidize electric furnace wires, shortening service life.
1 1. Even if there is no wind, the path of paper dropping is tortuous. This is because each part of the paper has different convexity and concavity and shape, so in the process of falling, the air speed on its surface is different. According to the principle of fluid mechanics, there is uneven air force everywhere on the paper, which changes with the movement of the paper, so the paper keeps rolling and falling zigzag.
5. Write a short article about physical invention, 1000 words, and discuss self-made batteries: some people make fruit batteries, and few people make vegetable batteries. Salt water, vinegar, alkaline water and sugar water batteries are actually good, but it is unprecedented to connect these batteries in series to make hybrid batteries!
It is better to have an ammeter for measurement. If you don't have an ammeter, buy a light-emitting diode, or remove the music bell from the greeting card and take some photos to match the paper. It is definitely the finishing touch!
Structure of the paper: 1. Ask questions (or research background)-organize or search 100-200 words.
Second, the research content: write out the process you did (as long as you actually did it, it's easy to write! ) 500-700 words
Three. Research conclusion:-Compile or search 100-200 words.
Fourth, problems and thinking: write about feelings, experiences, gains, improvements, exchanges, etc. 100-200 words
6. Physical phenomena in life Composition 800 words For physics, there are always people who find it difficult to learn and are afraid of physics. In fact, this is completely unnecessary.
Learning physics can start from life.
Now the physics we study is closely related to real life, and many far-reaching discoveries are born from life.
When studying physics in life, we should carefully observe the things around us, try to solve them by using what we have learned and explain the truth clearly. Pascal was full of curiosity about things when he was very young, and never thought that a thing "should have been ..." So under the guidance of this spirit, Pascal explored the principle of pronunciation when he was less than 10 years old. And has made outstanding achievements in physics.
Learning physics in life can not only be satisfied with the knowledge in textbooks, but also read more books after class and learn physics by modern means. In this way, we can better understand the knowledge in the textbook and be well informed. If we compare what we have learned to a ship, then to some extent, the knowledge gained after class is the river that carries the ship on a long journey. In this way, we can make continuous progress; If you can't do this, you will always stay in the realm of "knowing". Even if you get good grades, you can't make yourself feel satisfied and happy.
To learn physics in life, we must master the correct learning methods. Preview before class means that you have enough time to digest knowledge and pay attention to the important and difficult points in the textbook. After class, you should review, recite the laws of physics, and do more difficult and trapped questions, which will help improve your grades.
7. Composition 500 Feeling after learning physics. First, change ideas and reposition roles.
The new curriculum reform is a revolution of educational ideas, which requires teachers to "teach for quality". In the teaching process, the correct relationship of "teacher-led, student-centered" should be put right, the educational concept of "teaching for the sustainable development of mankind" should be established, and the role change from traditional knowledge disseminator to student development promoter should be completed. This is the same direction for the future development of teachers in all disciplines. Under the new concept of "student-oriented development", teachers' responsibilities are no longer single, but comprehensive and diversified.
Second, lifelong learning and optimizing the knowledge structure.
Physics is a very comprehensive natural subject, which requires physics teachers to have rich knowledge of physics and related disciplines and become a "multi-functional" compound talent in professional accomplishment. The new curriculum puts forward new requirements for physics teachers' knowledge structure and ability, and teachers should enrich and improve themselves through continuous learning. With the development of science and technology, the latest achievements in physics research are constantly emerging and constantly integrated into new textbooks. Therefore, teachers should learn these new knowledge and improve their knowledge structure; The new curriculum pays attention to the educational function of physics and advocates cultivating students' quality through physics education. However, due to the long-term influence of exam-oriented education, most physics teachers generally lack humanistic literacy. Therefore, teachers should learn rich scientific knowledge from human society and constantly improve their humanistic quality; The new curriculum also puts forward new ability requirements for physics teachers, such as the ability to communicate and cooperate with others, the ability to teach and research, the ability to integrate information technology with teaching materials, and the ability to design and develop courses.
Under the framework of new curriculum content, most teachers can't complete all the guidance work for students' projects by themselves because of their lack of comprehensiveness and foresight, which requires teachers to establish cooperative working ideas. From focusing only on this subject to other related subjects, from being used to narcissism to learning to appreciate the work and ability of other teachers, from completing teaching tasks independently to learning from each other's strengths together with other teachers.
Under the new situation, teachers are in the position of students' choice for the first time. They must re-examine their knowledge structure, internalize lifelong learning into self-study behavior, and always keep the attitude of learning, researching, reflecting, discovering, exploring, innovating and summarizing, so as to become an educator with profound knowledge, solid basic knowledge and modern information quality.
Third, people-oriented, innovative teaching mode
As the saying goes: there is no fixed method for teaching. In the teaching process, students' knowledge acquisition and the cultivation of intellectual and non-intellectual factors cannot be a single fixed teaching model. The teaching model involves three elements: knowledge, teachers and students. Teaching and learning are a dynamic process of common development. It is necessary to make clear the complexity of the teaching process, integrate the three elements, weigh the advantages and disadvantages, learn from others' strengths and flexibly choose teaching methods. We should not only reform and innovate, but also focus on reality and actively participate in creating heuristic, open, exemplary and cooperative teaching methods.
In the new curriculum reform, developing intelligence factors is not the whole of quality education. Non-intellectual factors such as students' learning purpose, interest, will, attitude and habit are the power system to promote the teaching process and realize the teaching effect, and play a role in starting, maintaining and regulating the students' learning process. Attach importance to the teaching of physics experiments and physics knowledge in teaching, and introduce stories, anecdotes and historical materials of physicists, so that students can understand the generation and development of knowledge and the role of physics in the long history of human development; Be good at comparing the differences between old and new knowledge, cause cognitive conflicts, cultivate students' questioning habits, guide students to find the internal relationship between current problems and their existing knowledge system, and strengthen problem awareness and innovative spirit; Finally, we should show students the ins and outs of knowledge through comparison, classification, analogy, induction and deduction, analysis and synthesis, and let them know why. "Learning begins with thinking, and thinking begins with asking". The classroom under the new curriculum standard should be like this: the classroom is not only the temple of subject knowledge, but also the temple of cultivating human nature. It is a temple for students to grow up, a sky for students to display their creativity and imagination, and a "dream theater" for students to taste life. Here, students have the experience of exploring and acquiring new knowledge, and their interest, enthusiasm, motivation, inner experience and inner world are all enriched. It is practical to reflect on physics teaching with personal experience, learning attitude and responsibility.
8. Write a short essay about physical invention, with more than 1 000 words. Pay attention to students' self-made batteries: some people make fruit batteries, and few people make vegetable batteries. Saltwater, vinegar, alkaline water and sugar water batteries are actually good, but connecting these in series to make a hodgepodge battery is an unprecedented initiative! It is better to have an ammeter for measurement. If you don't have an ammeter, buy a light-emitting diode, or remove the music bell from the greeting card and take some photos to match the paper. It is definitely the finishing touch! Paper structure: 1. Question (or research background)-compile or search 100-200 words. Second, the research content: write about the process you did (as long as you actually did it, it's easy to write! ) 500-700 words three. Research conclusion:-Compile or search 100-200 words. Problems and thinking: write about feelings, experiences, gains, improvements, exchanges, etc. 100-200 words.