I want experimental data on atmospheric pressure, and an experimental procedure for measuring atmosp

Measure atmospheric pressure.

The experimental procedure is as follows:

1. Experimental process: fill a glass tube about 1m long with one end closed with mercury.

After plugging the nozzle of the sequestration liquid, and then inserting it upside down in the mercury tank to release the finger blocking the nozzle, the mercury level in the tube will not fall if it drops a little, and the height difference between the mercury surface inside and outside the tube is about 760mm.

2. Principle analysis: take a liquid sheet in the pipe, which is level with the liquid level outside the pipe, and the liquid sheet is balanced by the pressure up and down because the liquid is not moving. That is, the upward atmospheric pressure = the pressure generated by the mercury column.

3. Conclusion: atmospheric pressure p0 = 760 mmHg = 76 cmHg = its value changes with the change of external atmospheric pressure).

4. Description: The purpose of filling the glass tube with mercury before the experiment is to make the glass tube inverted, and the mercury is above the vacuum; If it is not filled, the measurement result is on the low side.

In this experiment, if mercury is changed to water, a glass tube with a length of m is required

The glass tube is slightly lifted or pressed down, the height difference between the inside and outside of the tube remains unchanged, and the glass tube is tilted, the height remains the same, and the length becomes longer.

If the outside atmospheric pressure is h cmhg, try to write the pressure of the sealed gas (the liquid in the tube is mercury) in each of the following situations.

Magdeburg Hemispheric Experiment.

It was in 1654 that the then mayor of Magdeburg, Otto von Glick, was in the Holy Roman Empire.

A scientific experiment conducted in Regensburg (present-day Regensburg, Germany) with the aim of proving the existence of atmospheric pressure. The experiment was also known as the "Magdeburg Hemisphere" experiment because of Glick's title. The two hemispheres in which the experiments were conducted are still preserved in Munich.

of the Deutsches Museum.

In reality, there are also replicas for teaching purposes, which are used to demonstrate the principle of air pressure, and they are also much smaller in size than the hemispheres of those days. If the hemisphere was to be vacuumed, it would take sixteen more horses to pull it apart.

Conclusion

Magdeburg hemispheric experiments proved: atmospheric pressure.

Yes, and it's powerful. In the experiment, the air in the two hemispheres was pumped out, so that the number of air particles in the balls decreased and decreased.

The atmosphere outside the sphere compresses the two hemispheres together, so it is not easy to separate. The more air is pumped out, the atmospheric pressure on the hemispheres.

The larger it is, the less likely it is for the two hemispheres to separate.

After the oxygen in the bottle is burned, there is a pressure difference between the inside and outside of the bottle.

On June 20, 1643, the Italian scientist Torricelli first measured the value of atmospheric pressure by experiment, hence the name Torricelli experiment.

The principle of Torricia's experiment is that the value of atmospheric pressure is visualized, and mercury is used to it.

The height of the column is reflected in the fierceness. It can be understood as a communicator, the mercury in the tube and the atmosphere outside the tube, the pressure of the atmosphere on the mercury surface in the mercury tank and the pressure in the pipe and the mercury surface liquid bridge in the mercury tank are equal, and the pressure in the tube is generated by the mercury column in the tube, so the pressure of the mercury column in the tube is equal to the atmospheric pressure.

Under the action of atmospheric pressure, the height of the mercury column in the vacuum tube can be intuitively regarded as the strength of atmospheric pressure.

There are many small experiments on atmospheric pressure, and some of them are easy to draw from and simple to process. Here are some of the experiments on atmospheric pressure:

1. Preparation materials: 1 basin, 1 transparent glass cup, a candle (slightly shorter), water (red pen water can be added to the water, the vision is obvious).

The process of deferring the actual residue base: fix the candle on the bottom of the pot with candle oil. Next, pour the water into the basin (don't extinguish the candle). Then, place the clear glass cup over the candle. After a while, the candle went out and the water in the cup rose.

The principle of the experiment: there is about 1 5 oxygen in the air, and the burning of the candle consumes oxygen, so that the air pressure inside the glass is lower than that of the outside other, so that the water is pressed into the cup. The water in the cup was raised.

2. Prepare materials: a small suction cup, a thicker needle or awl, and appropriate weights.

Experimental process: Squeeze out the air with a small suction cup and stick it on a relatively flat wall. As a result, heavy objects can be lifted without external force, and then a small hole is poked in the surface of the plate at the end, and the small suction cup falls off immediately.

Experimental principle: the suction cup squeezes out the bright air, due to the atmospheric pressure, so that the suction cup can lift heavy objects, if the disc surface pokes a small hole, the air enters, the internal and external pressure is balanced, and the suction cup falls off, thus proving the existence of atmospheric pressure.

3. Prepare materials: a glass cup with a flat mouth, a flat piece of cardboard, and a few waters.

Experimental process: fill the glass with water, still use the cardboard lid to the mouth of the glass, hold it down with your hand, and turn it upside down (cup covering experiment): the glass is filled with water, the air is discharged, the pressure of the water in the cup on the cardboard is less than the atmospheric pressure, and the hard vertical mold paper is supported under the action of atmospheric pressure.

And when the rim of the cup is turned in a circle in all directions, the piece of cardboard does not fall off.

Experimental principle: There is atmospheric pressure, and the atmosphere has pressure in all directions.

4. Prepare materials: a small test tube and a few waters.

Experimental process: Immerse the small-caliber test tube in water, fill it with water and lift it upside down to the surface of the water, and the water will not flow out.

Experimental principle: the role of atmospheric pressure.

Experiment.

First, the principle is the effect of atmospheric pressure.

Experiment. Second, the principle is the effect of atmospheric pressure.

Experiment. 3. The water flows out quickly without the lid, and the water flows out slowly until it cannot flow out.

Cover the glass filled with water with paper so that the water does not leak when it is turned upside down.

In 1654 he heard about Torricelli, and that there were many people who did not believe in atmospheric pressure; A few people were also heard laughing at Torricia; Then I heard that the two sides were arguing fiercely, and they did not give in to each other, and they were-for-tat Therefore, although Glick was in Germany, far from Italy, he was very upset and indignant He hurried to find glass tubes and mercury, and re-did the experiment of Torricari, and concluded that it was accurate; The air is then pumped out of a well-sealed wooden barrel, and the barrel is "bang!" The sound was "crushed" by the atmosphere! One day, he and his assistant made two hemispheres, 14 inches in diameter, that is, more than 30 centimeters, and invited a large group of people to do a "large-scale experiment" on the outskirts of the city. On this day on May 8 of this year, the beautiful city of Magdeburg was sunny and sunny, the sky was clear, and it was very refreshing, and a large number of people gathered around the experimental field, bustling and shouting very lively. Some support Glick and hope that the experiment will be successful; Some assert that the experiment will fail; People are talking, arguing; is prophesying; Others shouted loudly while running through the streets and alleys to the experimental field:

The mayor is on a circus! The mayor played a circus——— Glick and his assistants put a rubber band in the middle of the brass hemispherical shell; Then fill the two hemispherical shells with water and put them together; Then all the water is pumped out to create a vacuum in the ball; Finally, tighten the faucet on the gas valve and close it At this time, the surrounding atmosphere pressed the two hemispheres tightly together With a wave of his hand, the four grooms led sixteen tall horses, and tied four horses on each side of the ball At the command of Glick, the four grooms whipped the horses and pulled them back! It's like a "tug-of-war" "Come on!

Come on! The black-pressed crowd on the experimental field shouted neatly while beating the beat 4 grooms, 16 big horses, all covered in sweat However, the copper ball was still intact Glick had to shake his hand and pause Then, the left and right teams, the number of people and horses multiplied The grooms drank some boiling water, wiped the sweat on their foreheads, and were preparing for a second performance Glick waved his hand again, and the experimental field was even more lively 16 big horses, desperately resisting, eight grooms were shouting loudly, whipping and urging the horses to ......The crowd on the experiment stretched their necks and watched vigorously, from time to time making a "Wow!" Wow!

Ladies! Citizens! You should believe it!

The atmospheric pressure is there, and the atmospheric pressure is so great! So amazing! ......

Experiments and phenomena of atmospheric pressure.