Seek to explain the principle of a simple barometer and some of the doubts.

1. The two arrows indicate the direction of the gas pressure in the bottle, and the external atmospheric pressure is not a certain value, which is not equal to the pressure of the air part in the bottle, but the pressure of the gas in the bottle minus the pressure of the water.

It's different, because in order to see the change in atmospheric pressure, the water surface in the tube is generally a little higher.

Because carbon dioxide dissolves in water, the amount of gas decreases, resulting in a decrease in gas pressure, and you can't blow in, because the pressure generated by the extrusion of your mouth, the effect of compressed gas is too small, and there is also pressure on the water column in the straw, which is atmospheric pressure, and the direction of the force is downward for the water surface.

Because the gas pressure in the bottle is stronger than the atmospheric pressure, the atmospheric pressure is not a fixed value.

No, the atmosphere is fluid pressure, which is in all directions, and the squeezing of the palm of the hand has only one direction.

I'm exhausted!

At this time, the bottle is sealed, the air can not circulate, and the pressure of the outside world changes, just like as a hand, if the pressure of the outside increases, it means that the bottle is pinched by hand, but the gas in the bottle can not come out, and the volume does not change, then the water column rises, which is the change caused by the bottle being squeezed. The arrow indicates the pressure generated by the bottle being deformed under pressure, but unable to release the gas. The external pressure is the weight of the rising volume of the water column and the weight of the pressure.

CO2 reacts with water, the volume of the gas decreases, the pressure decreases, and the bottle is pinched flat. However, when carbon dioxide reacts with water, it is a mild reaction and is not obvious enough when the pressure is too small.

Carbonic acid is produced. But a small amount. There is pressure, but it is negligible because of the small force area and the small effect on water. But the gravity of the water column has to be calculated, which is the weight of the volume of the water column. The direction of gravity is downward.

The outside pressure is high. Generate pressure, such as pinching a bottle by hand.

1. Mercury barometer.

The principle of the Torricelli experiment. The height of the mercury column supported by different atmospheric pressure is different, according to p = p (mercury density) hg, the calculated pressure is equal to the atmospheric pressure, of course, this calculation makes the barometer calculated and marked on the barometer, and the magnitude of the air pressure can be known through the scale of the mercury face.

2. No liquid barometer.

Aneroid barometers are a type of barometer, the most common being a metal box barometer.

Its main part is a vacuum metal box with a corrugated surface. In order not to flatten the metal box by atmospheric pressure, it is pulled outwards with an elastic steel sheet. The atmospheric pressure increases, and the lid is recessed a little; When the atmospheric pressure decreases, the elastic steel sheet pulls the lid up a bit.

The change in the lid is transmitted to the pointer through the transmission mechanism, which deflects the pointer. From the reading on the dial below the pointer, you can know the value of the atmosphere at that time.

How it works: The principle of equilibrium of atmospheric pressure.

When the atmospheric pressure inside and outside the bottle is the same, the liquid level height inside the straw is the same as the liquid level height inside the bottle, when there is a difference between the pressure inside the bottle and the outside of the bottle, at this time, the difference between the two will occur, which is the working principle of a simple barometer.

The equilibrium principle of atmospheric pressure, when the atmospheric pressure inside the bottle and outside the bottle is the same, the liquid level height inside the straw and the liquid level height inside the bottle are the same, when there is a difference between the pressure inside and outside the bottle, at this time, the difference between the two will occur, this is the working principle of a simple barometer!

Summary. Hello, it's a pleasure to answer for you. A simple barometer usually consists of a sealed glass bottle and a transparent hose.

When the hose is inserted into the bottle and the mouth of the bottle is tightly closed, the air inside the hose is enclosed inside the hose and the bottle. At this point, the air pressure inside the bottle is equal to the air pressure inside the hose, as the gas spontaneously diffuses to all areas of the container in a uniform state. When measuring air pressure with a simple barometer, one end of the hose is exposed to outside air, while the other end remains enclosed inside the bottle.

The air pressure inside the bottle changes due to the difference between the outside air pressure and the air pressure inside the bottle. At this point, the air inside the hose spreads into the bottle, reducing the volume of gas in the hose. Therefore, the pressure inside the hose will change with the change in the air pressure inside the bottle, while the volume of the hose remains the same.

Since the bottle is sealed, no gas enters or exits, so the volume of gas inside the bottle remains the same. Therefore, when the outside air pressure changes, the air inside the hose will move back and forth between the hose and the bottle to reach an equilibrium state, so that the air pressure inside the hose is equal to the air pressure inside the bottle. Therefore, there is no change in the air pressure inside the bottle.

In general, the working principle of a simple barometer is based on the principle of gas diffusion and pressure equilibrium, which indirectly measures the outside air pressure by measuring the pressure change of the gas inside the hose. Hope mine is helpful to you! If you are satisfied with my service, you can give me a thumbs up!

Hello, it's a pleasure to answer for you. A simple barometer usually consists of a sealed glass bottle and a transparent hose. When the hose is inserted into the bottle and the mouth of the bottle is tightly closed, the air inside the hose is enclosed inside the hose and the bottle.

At this point, the air pressure inside the bottle is equal to the air pressure inside the hose, as the gas spontaneously diffuses to all areas of the container in a uniform state. When measuring air pressure with a simple barometer, one end of the hose is exposed to outside air, while the other end remains enclosed inside the bottle. The air pressure inside the bottle changes due to the difference between the outside air pressure and the air pressure inside the bottle.

At this point, the air inside the hose spreads into the bottle, reducing the volume of gas in the hose. As a result, the pressure inside the hose will change with the air pressure inside the bottle, while the volume of the hose remains the same. Since the bottle is sealed and the sails are messy, there is no gas in and out, so the volume of gas inside the bottle remains the same.

Therefore, when the outside air pressure changes, the air inside the hose will move back and forth between the hose and the bottle to reach an equilibrium state, so that the air pressure inside the hose is equal to the air pressure inside the bottle. Therefore, there is no change in the air pressure inside the bottle. In general, the working principle of the simple barometer is based on the principle of gas diffusion and pressure equilibrium, which indirectly measures the pressure change of the gas in the hose to measure the pressure of the gas in the hose.

Can you add, I don't quite understand it.

Based on the principle of gas diffusion and pressure equilibrium, the outside air pressure is measured indirectly by measuring the pressure change of the gas inside the hose.

The principle of self-made barometer is: the air pressure in the bottle is equal to the pressure of the water column in the glass tube to increase the air pressure, and the atmospheric pressure decreases with the increase of height, when the barometer is taken from the sixth floor to the first floor, the atmospheric pressure increases, and the air pressure in the bottle remains unchanged, so the water column in the glass tube decreases So the answer is: decrease

1) Bring the barometer from the foot of the mountain to the top of the mountain, the pressure of the air in the bottle remains unchanged, and the outside atmospheric pressure decreases with the increase of height, at this time, under the action of the air pressure in the bottle, a part of the water will be pressed into the glass tube, so the height of the water column in the tube will increase; (2) With these equipment, the experimental device that can also be self-made is the mercury barometer; So the answer is: get bigger; Atmospheric pressure decreases with increasing altitude; Mercury barometer

1) When the external atmospheric pressure of the rolling material decreases, the pressure inside the bottle is stronger than the atmospheric pressure, so the height of the liquid column in the thin tube will rise; (2) Since the mass of the object does not change with the change of air pressure, the pressure of the bottle on the table does not change, so choose A

The atmospheric pressure decreases with the increase of altitude, so the atmospheric pressure from the foot of the mountain to the top of the mountain will decrease, and because the pressure of the air in the bottle remains unchanged, under the action of the air pressure in the bottle, a part of the water will be pressed into the glass tube, so that the water column in the tube rises, so the ACD does not meet the topic; Therefore, choose B

The pressure of the closed gas in the bottle P is equal to the sum of the atmospheric pressure P0 and the pressure generated by the water column in the glass tube, that is, P = P0 + Gh, H is the height of the water column in the glass tube In the process from the foot of the mountain to the top of the mountain, the gas pressure P in the bottle remains unchanged, and the atmospheric pressure P0 becomes smaller, so the h strain is large, and the water column in the glass tube rises Therefore, A is selected

The picture is a self-made barometer with a large slow liquid, Xiao Ming used a tray to support it from downstairs to upstairs, and found that the height of the water column in the glass tube had become higher. (1) The height of the water column becomes higher.

1) Decrease (2) Decrease.

As shown in the figure, the principle of the barometer is: the air pressure in the bottle remains unchanged, it is equal to the sum of the atmospheric pressure and the pressure generated by the water column in the thin glass tube, when the height increases, the atmospheric pressure decreases, and the pressure generated by the water column in the fine glass tube increases, so the ACD error is selected B

The atmospheric pressure decreases with the increase in altitude, so that when the atmospheric pressure decreases, the liquid column rises under the action of the internal pressure; The water column rises, the water surface in the bottle decreases, the volume of air increases, and the mass remains unchanged due to sealing, so the density of the gas will become smaller, so the answer is: decrease, unchanged, and become smaller

The empty box barometer is a relatively common barometer, and its working principle is to use the elastic deformation displacement of the diaphragm box by atmospheric pressure, and make the self-recording pen tip record on the time pressure coordinate record paper with the corresponding air pressure value through the transmission conversion mechanism, and form a time recording curve to measure atmospheric pressure. The empty box barometer is divided into two types: diary type and weekly type according to the recording period.

The empty box barometer is an empty box group that moves axially with the change of atmospheric pressure as an induction element, and it drives the pointer through the pull rod and transmission mechanism to indicate the atmospheric pressure value at that time.

The disadvantage is that it is inconvenient to carry.

Ideal gas equation: PV=NRT; The amount and volume of a certain amount of gas are constant, so p is proportional to t.