Machinery in the life of physics essays in the second day of junior high school

1, water pressure handle of hydraulic well:

Using the lever principle, the fulcrum is closer to the well and the handle is longer, which makes the arm of force longer and more labor-saving. However, according to the principle of lever, lever is economical rather than labor-saving.

2. Bicycle:

There are many small mechanical devices on bicycles, which are the most typical mechanical devices in life.

For example, the brake is made by using the lever principle.

The pedal is actually a crank mechanism.

The front sprocket and the rear sprocket are connected by hinges, which is a simple chain transmission mechanism in terms of mechanical principle.

3. Pliers and scissors

It is also made by using the lever principle. In fact, two small levers are combined to form a pair of pliers or scissors.

4. Wrench

Or the lever principle.

5. Small hydraulic jack

(I don't know if the landlord saw that many drivers' cars broke down on the street, so they took them out of the trunk and put the roof up for repair. This is a routine project for drivers. )

The internal structure is a simple hydraulic device. In principle, there is also the application of the lever principle. Although the hydraulic jack is small, it is easy to install the car.

6. Electric screen

This thing is widely used in rural areas. When grain is placed on it, the electric screen will automatically swing to screen out useless things.

Its principle is a double rocker mechanism, which belongs to a four-bar mechanism in a big classification.

The earth is equivalent to a pole, the two swing supports are the second pole and roof of the world, and the sieve is the fourth pole.

Those who have studied mechanical principles know that four-bar mechanism can form crank-rocker mechanism, double-rocker mechanism and double-crank mechanism according to the length relationship between four bars.

The electric screen is a manual double rocker mechanism.

7, the door of the car

The specific structure is of course very complicated, but in principle, the door is actually a simple four-bar linkage.

8. Piston pump

I don't know if you've seen it, but it's similar to a bicycle pump, which pumps water or oil up by the plunger inside.

Its principle is actually a crank-slider mechanism, and the plunger is equivalent to a slider.

The crank-slider mechanism is actually a variant of the crank-rocker mechanism, and as mentioned earlier, the crank-rocker mechanism belongs to the four-bar mechanism in a big classification.

9. Elevator

In fact, the internal structure of the elevator is very complicated, either as people think, or an elevator car is hung by a steel cable. Now all kinds of automatic control devices, all kinds of sensors and, of course, the most important safety protection devices are integrated in the elevator.

But from the mechanical principle, the elevator is actually a worm gear mechanism. In the big classification, worm gear mechanism belongs to a kind of gear mechanism.

10, gear pump

A simple pump, used to pump water or oil, is very common in life.

This is a typical gear mechanism.

Take the gear pump apart. There are actually two gears in it.

The advantages of gear pump are low cost and small volume, but the disadvantages are high working noise and small displacement.

To sum up 10! !

In fact, there are many simple mechanical devices in life, which can be said to be everywhere.

If you give a few more complicated examples, there will be more!

For example, if you want to disassemble the gearbox of a car, it is full of gears, which belong to the gear system, and the gear system also belongs to the gear mechanism in a large classification.

The crane on the construction site has lever, four-bar linkage, gear, hydraulic and pulley block. . . . too much

Lathe, have you seen it? It includes almost all mechanical devices.

A car also includes almost all the mechanical devices you can think of.

So as long as you pay attention to observation, machinery in life is everywhere.

The following article:

Theme: life mechanization

I have been engaged in agricultural machinery science and technology for 20 years, participated in the research and development and promotion of new agricultural tools, and realized mechanized operation. The guiding ideology is that "the fundamental way out for agriculture lies in mechanization" put forward by President Mao Zedong. But he also said, "Eating can't be mechanized". As far as I know, this "eating" refers to all kinds of life matters vividly.

Can you walk? /kloc-I was a soldier in 0/0. I March to fight, and walking is the basic skill. After demobilization, I lifted my legs and left, not to mention. Nowadays, my young friend refuses to walk two or three miles. Take the bus when you go out, drive, nourish your stomach, and have high blood pressure. Go to the treadmill and sweat when you get home. This is called weight loss mechanization.

I am a fan, and I also pay attention to all kinds of sports games. Recently, the American athlete's 100-meter record of 9.76 seconds was cancelled. It turns out that the electronic instrument (which can distinguish one thousandth of a second) judged that his score was 9.766 seconds. According to the rules, only the original record of 9.77 seconds was tied. This shows the progress of science and technology. Otherwise, how can you tell with the naked eye and a stopwatch? I often feel angry and sorry for the "black whistle", misjudgment and missed judgment on the court, but I can't accept the "machine referee". Because football is a comprehensive art, including the level of referees and even the quality of fans, everyone is flesh and blood, and coaches, players and fans will make mistakes. Why are referees not allowed to make mistakes? In this sense, success, failure, impatience, composure, foul, diving, misjudgment, missed judgment, penalty kick and own goal are intricately intertwined, full of suspense and charm. "Football is round." Do you know where it jumped? If there is a robot referee, the players are all robots and always correct, wouldn't it be sad!

Shopping malls sell smart dolls, which are expensive and sell best. They have vision, hearing and touch, can speak a thousand sentences and can talk to you (sold abroad, they speak foreign languages). They are very popular with children and parents, especially the only child who lacks playmates. There are more advanced electronic nannies in Europe and America, which can do all kinds of housework and take care of children. In addition, automatic office, intelligent residence, automatic opening and closing of doors and windows, washing, eating, writing, calculation, entertainment and hibernation are all controlled by computer programs, and the living will also be simplified as gears and screws of the whole machine.

American intelligent robot "Deep Blue" can beat the world champion when playing chess. Computer-drawn three-dimensional images have replaced stuntmen, so it is difficult to distinguish between true and false. Even more frightening is that intelligent robots can also write novels, just to capture Nobel Prize in Literature. We used to oppose formulaic and conceptual creative methods, and robots must write novels from established models, which makes the thing of "a thousand people and a thousand departments" come back. I have experience in this matter. I wrote 16 years on the computer. I not only lost the manuscript, but also forgot the words. What's more embarrassing is that I'm still struggling with the software. For example, when I want to write about Li Bai, as long as I enter the word Li, it immediately "associates" the names of a series of leaders such as Li Ruihuan and Li, that is to say, I can't "think" that there is a great poet Li Bai in China; I'm going to write "Kingoma Iron", and then I'll come out. Gorbachev, alas, what does this have to do with me? In order not to let it lead by the nose, I have to type and make sentences myself. If I am lazy, my novel will lose its personality and fall into a dry official document nest.

Once I took a taxi in new york, the meter showed $28. I gave him 58 yuan and told him to take it back to 30 yuan. The driver frowned and said, "It has always been 28 yuan. Why should I give you 30 yuan?" This is no joke. There are 3 million new illiterates in modern America and Britain. After graduating from college, they can't write letters, read books, calculate, or even recite "Nine Nine Tables". The reason is that they have watched TV since childhood, without reading newspapers or even "picture books". Who writes when you have a mobile phone? Living in the computer age, why bother to calculate how many heads and feet there are in the "chicken rabbit cage"! These functions are underdeveloped, so new illiteracy is also called functional illiteracy.

Do our children spend too much time watching TV and surfing the Internet? Can all of us college students write letters? China has more color TV sets and mobile phones than Britain and the United States combined. Will there be new illiteracy? Life is too convenient, whether it leads to the decline of human function, and there are many "rich diseases", which are gradually drifting away from a sound life and drifting away. ...

Article 2:

Theme: machinery and life

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Do it yourself, have plenty of food and clothing!