Atmospheric pressure. Due to the action of gravity, air will exert pressure on objects immersed in it, that is, atmospheric pressure, which is abbreviated as atmospheric pressure. Because air is mobile, there will be pressure in all directions. At the same point, the pressure of air in all directions is equal.
In life, there are also suction hooks that use this principle. When the suction hook is forced against the wall, the air in the suction cup is squeezed out, so that the air pressure in the suction cup is smaller than that outside the suction cup, and the air pressure outside the suction cup presses the suction cup against the wall. Similarly, there are pumps, toilets, water pumps, syringes for injections, and pens for absorbing ink.
Extended data
The invention of straw:
The straw was invented by Marvin Si Tong of the United States in 1888. At that time, in America, people liked to drink cold wine. If you drink directly into the cup, the hot air in your mouth will reduce the iced taste of the wine, so at first they tried to suck it with a natural straw. This will solve the problem.
However, the natural straw is easy to break, and the taste of the straw itself will be mixed into the wine, affecting the purity of the wine. This problem has never been solved. At that time, Marvin Si Tong was a cigarette manufacturer. One day, inspired by cigarettes, he made a straw out of paper. He found it very convenient and easy to use, and there was no smell.
In this way, paper straws have been widely used. After the invention of plastic, because plastic is flexible and beautiful, it can be made into various colors. People improved paper straws and adopted plastic straws. This is how the straw was invented. Unfortunately, Marvin Si Tong didn't apply for a patent for invention.
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