On the question of air pressure. There are three reasons that affect air pressure that you must know

For example, when ground A is heated and the air flow rises, then the air pressure near the ground of A forms a low pressure relative to the same horizontal plane, a near the ground is low pressure, and the others are high pressure, so the air flow from other places is made up to the near ground of a, and the air flow above is high pressure due to the rise of the air flow near the ground, and because the air flow always flows from high pressure to low pressure, so the air pressure in the same horizontal plane is low pressure relative to the high pressure at high altitude, so the air flow is from high pressure to low pressure

Again, if you say that b is low and the air sinks, it creates high pressure, and the same level is low, so from the near ground of b, the air flow is diffuse, and the high altitude of b is low pressure because of the air sinking, and it is low pressure from a horizontal plane, and the air flow flows from the four directions to the high altitude of b

In short, the comparison of the air pressure is compared from the horizontal direction Remember that the air pressure at high altitude is always lower than that on the ground What was said above was not checked There may be some errors If there are any, please forgive me...

Compare the air pressure from the horizontal direction.

Remember: the air pressure near the ground is always higher than the air pressure at the top!

The high air pressure formed above ground A is relative to the air pressure above ground B at the same height, not relative to place A!

Similarly, the low air pressure above ground B is not relative to the air pressure at ground B, but is lower than the air pressure above place A at the same level.

There are three reasons that affect air pressure that you must know!

The structure of a car tire determines that it is only inflated once in a long time.

Affects the air pressure value of the car's tires.

1. The tightness of the valve.

When pumping car tires, it is injected from the air ridge posture door mouth, and it needs to be pressed inside to pump normally.

2. The tightness of the wheel hub and the tire.

Because the car tire is closely matched with the wheel hub and the tire to form the function equivalent to the inner tube, so the fit between the hub and the tire is quite important, if your wheel hub has been deformed after the accident impact, it may lead to a decrease in the fit, the tire will leak faster, generally speaking, the original fit is qualified.

3. The quality of the tires.

The quality of the tire will also affect the air pressure of the tire, choose a brand tire, and buy it from regular channels, there will generally be no quality problems, in addition, the tire has a life, the material of the tire is rubber, the rubber will age over time, and it will also age with the increase in mileage, once the tire is aged, there will be a risk of air leakage, and there is a risk of puncture.

4. The use of tires.

During the use of the tire, each surface of the tire will rub against the ground, and the pressure is uniform, so there is less air leakage, and due to the friction heat, the internal air pressure and temperature will increase, resulting in a closer combination between the wheel hub and the tire, as long as you are in normal use, as long as the tire is not broken, there is no need to inflate.

1. When cooking, there is a lot of "white gas" in the kitchen shed - first a large amount of water vapor produced by water vaporization, and small water droplets formed by water vapor when it is cold and liquefied in the process of rising.

2. Cooking utensils such as spatulas, hand spoons, colanders, and aluminum pots are all made of wood or plastic - wood and plastic are poor conductors of heat so that they do not burn their hands during cooking.

3. When the car brakes (decelerates) suddenly:

1. The driver applies the brakes - the force is the reason for changing the motion state of the object.

2. Passengers will dump in the direction of the car - inertia.

3. The driver can brake the car with less force - the principle of leverage.

Fourth, the fountain pen absorbs ink is the use of atmospheric pressure, when absorbing ink, first squeeze the pen bag to remove the air inside, and then put the tip of the pen into the ink, let go of the hand, and the atmospheric pressure will press the ink into the pen bag.

5. Why can airplanes fly into the sky? Because the wings are subjected to upward lift. The streamline distribution of the air around the wing during flight refers to the asymmetry of the shape of the cross-section of the chain slag spike wing, the streamline above the wing is dense and the flow velocity is large, and the streamline below is sparse and the flow velocity is small.

From Bernoulli's equation, the pressure above the wing is small, and the pressure below is strong. This creates a lift force in the direction acting on the wing.

6. Tungsten filament for filament - tungsten filament has a high melting point and is not easy to melt at high temperatures.

Categories: Education, Science, >> Science & Technology.

Problem description: During the Magdeburg hemispheric experiment, if the atmospheric pressure was standard atmospheric pressure at that time, the pressure of the remaining air in the ball would be a standard atmospheric pressure after the first pumping; After the second pumping, the pressure of the remaining air in the ball is one standard atmosphere. In these two cases, the ratio of the tensile force used to pull the two hemispheres apart is f1:f2

Analysis: At that time, the atmospheric pressure was one standard atmosphere (1atm) for the first pumping.

If the pressure inside the ball is sailing, then the difference between the internal and external pressure is δp1=(

Second pumping.

The pressure inside the sphere is , then the difference between the internal and external pressure is δp2=(

The area where the atmospheric pressure acts is the same.

Pressure f=ps

The ratio of the pressure difference between the two times.

f1δ/f2=（δp1*s）/(p2*s)=

Barometric pressure is the atmospheric pressure acting on a unit area, i.e., the gravitational force exerted on a vertical column of air that extends up to the upper boundary of the atmosphere per unit area. The famous Magdeburg hemispheric experiment proves its existence. The international unit of air pressure is Pascal, abbreviated as Pa, and the symbol is Pa.

In meteorology, people generally use kilopascals (kpa) or hectopa (hpa) as the unit. Other commonly used units are: bar (1 bar = 100,000 Pa) and centimeters of mercury (or centimeters of mercury).

Air pressure varies not only with altitude but also with temperature. Changes in air pressure are closely related to weather changes.

Barometric pressure is the atmospheric pressure acting on a unit area, and the international unit of air pressure is Pascal, referred to as Pascal, and the symbol is Pa.

Barometric pressure is the atmospheric pressure acting on a unit area, i.e., equal to the weight of a column of vertical air per unit area that extends upwards to the upper boundary of the atmosphere. The famous Magdeburg hemispheric experiment proves its existence. The international unit of air pressure is Pascal, abbreviated as Pa, and the symbol is Pa.

Two objects with mass have a gravitational attraction to each other, and the heavier the mass of the object, the greater the attraction; The smaller the distance between objects, the greater the attraction. There is no difference between objects in the universe, and people can not fall into the air on the surface of the earth, mainly because the earth and people attract each other.

That's what air pressure means. Air, like other substances, has a certain mass, and the gravitational pull between the air and the earth forms weight, and the pressure generated by weight is called pressure measured per square meter, and for the atmosphere it is called barometric pressure. The heavier molecules in the air are closer to the surface of the earth, and the lighter are far from the surface, the denser the air is closer to the ground, and the thinner it is the farther it is.

Where the air is thin, the air density is small and the weight is light, and the weight pressure generated is small, that is, the air pressure is low.

I don't know if it's popular enough? There are many factors that affect air pressure, and here is just an analysis of the main ones.

What is the air pressure is as follows:

The principle of the egg eating bottle experiment: because of the existence of atmospheric pressure, when the air in the bottle is less and less, the outside atmospheric pressure will press the egg in.

Experiment: 1. Peel off the hard-boiled egg shell.

2. Tear the paper into long strips.

3. Toss the lit note into the bottle.

4. After the fire in the bottle is extinguished, immediately put the egg into the mouth of the bottle, and then remove the hand, the egg is slowly sucked in by the bottle and falls into the bottle.

Barometric pressure is short for atmospheric pressure, which is the atmospheric pressure acting on a unit area, that is, equal to the weight of the vertical column of air that extends upward to the upper boundary of the atmosphere per unit area. The magnitude of the air pressure is related to the altitude and temperature of the orange bushes. Generally, it decreases with increasing height.

In the horizontal direction, the difference in atmospheric pressure causes the movement of air.

A unit of air pressure, and it is customary to use the height of the mercury column. For example, a standard atmospheric pressure is equal to the pressure generated by a 760 millimeter-high column of mercury, which is equivalent to the atmospheric pressure of a kilogram on an area of one square centimeter. It is used in an international uniform manner"hPa"As a unit of air pressure.

After conversion: one standard atmosphere = 1013 hPa (mbar).

Atmospheric pressure refers to the weight of the atmospheric column per unit area. In meteorology, it is often expressed in millibars or millimeters of mercury column height. A standard atmospheric pressure is millibar, or the equivalent of a column of mercury 760 mm high.

Since the higher the air pressure above the ground, the lower the air pressure, so the altitude can be measured based on the change in the vertical direction. In the horizontal direction, the difference in air pressure can cause the flow of air, so it is one of the important meteorological elements for analyzing weather forecasts.

First of all, you don't use a trachea, because the trachea is ventilated at both ends. You're supposed to be using a test tube.

Secondly, the atmospheric pressure plus water pressure is much larger than the air pressure in the tube? In fact, the big difference is the water pressure at the horizontal position of the nozzle, because the inside of the pipe is atmospheric pressure, and the outside of the pipe is atmospheric pressure + water pressure.

If you do the math of the difference, which is the water pressure at this depth, it's actually very small, it's not enough to compress the air in the tube and squeeze the water into it (in fact, there is still a little bit of water being pressed into it, but this value is too small and too small), and if you dive deep enough, then you can see that some of the water will enter the duct. If it's deep, it's deep, it's deep... Then your tube will explode...

It's too much pressure ...

The trachea should form a negative pressure before water can enter, you first seal a head of water!

The atmospheric pressure at the same altitude is equal, unless the air in the duct is removed first.

Water pressure and air pressure are equal; One kilogram of air pressure is equal to one kilogram of air pressure.

Formula P Water = PGH

It's just the pressure generated by the water, not the air pressure, in fact, the person is 2m underwater

The pressure to be subjected to.

It should be the pressure of the water plus the air pressure at that time.

Just say"Water pressure at a depth of one meter", which has nothing to do with atmospheric pressure.

If it is said"What is the pressure at a depth of 1 meter in water? "When the atmospheric pressure value is given, the pressure here should be equal to the water pressure at a depth of 1 meter, plus the atmospheric pressure at that time.

The residual air in the air duct passes through the water pressure at the mouth of the air duct plus the pressure of the atmosphere, and it will be compressed, knowing that it is equal to the sum of the outside water pressure and atmospheric pressure.

The discomfort in the water is mainly chest tightness, in the standard atmospheric pressure, the lungs and the outside world are connected, the internal and external pressure is balanced, so you will not feel uncomfortable, after immersion in the water, the pressure on the outside of the body is equal to a standard atmospheric pressure plus the pressure of the water, the external pressure is greater than the internal pressure, so there will be a sense of pressure, if the lungs can be filled with water, and the external water is connected, it will not feel any discomfort (of course, it is not possible).

If you are two meters in the water, you will bear it.

The atmospheric pressure is combined with the pressure created by two meters of water.

Because there is already one on the surface of the water.

Atmospheric pressure.