What is the magic of air pressure?

The whole lake turned red (it was blood), and a hand was stretched out from the lake, and the girl's feet were grabbed, and she was pulled into the lake, and then, 100 kilometers away from the forest, the girl's body and clothes were found, but her head was missing, and the people opened her backpack and were frightened, and the bag was her head, and her expression was very painful, and the people who found her had abandoned her body in the forest, and then left, and since then, no one has dared to go to that forest.

If you read this post, please reply to the post immediately, and click "Bodhisattva bless", and then post this in another bar **3 copies, if not, that hand will be stretched out when you take a bath, and you will end up with that girl! Be sure that everything is true.

1 The pump is a common tool made of the relationship between gas pressure and volume. There is a piston in the pump, and there is a concave rubber disc on it, when the piston is pulled up, the volume of air under the piston increases, the pressure decreases, and the air above the piston is squeezed from the rubber disc to the bottom; When the piston is pressed down, the volume of air under the piston decreases and the pressure increases, so that the rubber disc is pressed against the cylinder wall to prevent air from leaking above the piston; Continue to press down on the piston, and when the air pressure is strong enough to open the rubber sleeve on the tire valve (the valve is a one-way valve), the compressed air enters the tire.

2 Pumping machine aka. Water pump. It is a hydraulic machine that uses atmospheric pressure to lift water from a low place to a high place.

It consists of a water pump, power machinery and a transmission device. There are many types to suit different needs. Commonly used are:

Piston pumping. And. Centrifugal water pump.

The structure of the piston pumping machine is simple, easy to operate, but the water output is small, and in the actual case of energy loss, the height of the water can only reach about eight meters, and the efficiency is also low. Centrifugal water pump is a kind of pumping machinery that uses the centrifugal movement of water, its water output is large, the water lifting height is high, and it is widely used in farmland irrigation, drainage and water supply and drainage of industrial and mining enterprises and towns. True:

1.Hot air balloon ascent.

2.Straw. 3.Vacuum cleaner.

4.The fountain pen absorbs ink.

5.Pumping machine principle.

That's detailed enough, that's it.

Drink with a straw, communicator.

Cupping, dripping, pressure cooker, straw, syringe, pen to absorb ink.

The effect of air pressure on human physiology is mainly the ** that affects oxygen in the human body. People need about 750 milligrams of oxygen per day, 20% of which is consumed by the brain, which has the highest oxygen demand. When the natural air pressure drops, the partial pressure of oxygen in the atmosphere, the partial pressure of oxygen in the alveoli, and the oxygen saturation of the ulnar artery all decrease, resulting in a series of physiological reactions in the human body.

For example, when climbing from the lowlands to the mountains, the body accelerates breathing and blood circulation in order to compensate for the lack of oxygen, resulting in shortness of breath and increased heart rate. Due to the lack of oxygen in the human body (especially the brain), symptoms such as dizziness, headache, nausea, vomiting and weakness also occur, and even pulmonary edema and coma can occur, which is called altitude sickness. At the same time, air pressure can also affect the psychological changes of the human body, mainly causing people to suppress emotions.

For example, rainy and snowy weather under low atmospheric pressure, and hot and humid weather before a thunderstorm in summer, often cause depression and discomfort. When a person feels depressed, the autonomic nervous system (autonomic nerve) tends to tension and releases adrenaline, causing blood pressure to rise, rapid heartbeat, shortness of breath, etc. At the same time, cortisol is decomposed and released, causing increased gastric acid secretion, blood vessels prone to infarction, and blood sugar levels rise sharply.

In addition, the minimum monthly pressure is closely related to the occurrence of the peak of population death. Some scholars studied the lowest value of the current month for 72 months, and found that there were 64 death peaks within 48 hours, and the probability of occurrence was as high as 88 9%. [

Application 1: The greater the pressure, the higher the boiling point of the slag water, and the easier it is to cook the boiled product. Example: High pressure is prudent.

Application 2: When filling the kettle with wide and cautious water, it is generally necessary to leave a certain amount of space, so that the water will be kept warm for a longer time (hehe, I'm not sure about this).

Application 3: High temperature and low air pressure. Example: The stopper of a kettle.