Why was there the Torricelli experiment and then the Magdeburg hemispheric experiment?

The book you read is simply misleading, of course, there is the Magdeburg hemispheric experiment, and then there is the Torricelli experiment, the Magdeburg hemispheric experiment is to discover the existence of atmospheric pressure, and found that the atmospheric pressure is very large, and the Torricelli experiment is to measure the value of atmospheric pressure, our physics tree says so, it is the first semester of the ninth grade of the second phase of the Shanghai curriculum reform.

This ......History is like this (I haven't paid attention to it) It's nothing, why the Magdeburg hemispheric experiment proved that atmospheric pressure exists, but it's not the first time that Magdeburg has done this experiment, so he must have known about the existence of atmospheric pressure (and the value) before, maybe people didn't have an intuitive understanding of the magnitude of atmospheric pressure at the time, and Magdeburg wanted to show people.

The Magdeburg Hemispheric Experiment is not an exact physical experiment and is a bit of a sensationalism (I'm not belittling Magdeburg).

No, it's because Magdeburg is the mayor and the experiments he did in front of the public were convincing; And Torricelli was an experiment done in the laboratory, and there was no evidence, so at that time people thought that it was the atmospheric pressure discovered by Magdeburg

There should have been the Magdeburg test first, and then it was proved that the magnitude of the atmosphere was magnitude, and it seemed that there was a difference of 11 years.

...It was Torricelli who had the Madebao hemisphere test first. That's what it says in the book.

In 1643, Torricelli, together with Viviani, another younger pupil of Gagatro Lillo, did the famous "Torricelli Experiment" in Florence. Fill a glass tube about 1m long with mercury at one end, plug the pass with your fingers, and then insert the inverted key into the watermark slot for revision. Let go of the finger, the mercury level in the tube will not fall when it drops to a certain height, and the difference between the mercury inside and outside the tube is about 760mm.

In the square of the city of Magdeburg, Germany, a famous Hemispheric experiment was carried out in 1654. Combine two copper hollow hemispheres with a radius of about 20 cm, drain the air inside, and use two horses to pull the two hemispheres in opposite directions.

To sum up, Torricari experimented early.

Summary. Hello, Torricelli Experimentator (J2116 type), mercury, 1 meter or more long glass tube (or two glass tubes connected with a rubber tube in between), sink (beaker). On June 20, 1643, the Italian scientist Torricelli first carried out this experiment, hence the name Torricelli experiment.

This experiment measured a standard atmospheric pressure of about 760 mm Hg or a column of water.

Torricelli experiments.

Hello, Torricelli Experimentator (J2116 type), mercury, 1 meter or more long glass tube (or two glass tubes connected with a rubber tube in between), sink (beaker). On June 20, 1643, the Italian scientist Torricelli first carried out this experiment, hence the name Torricelli experiment. This experiment measured a standard atmospheric pressure of about 760 mm Hg or a column of water.

Standard atmospheric pressure p = kilogram cubic meter Newton kilogram meter Newton square meter = Pascal =1atm =76cmHg =760 Torr =760mmHg 1mmHg =

Is the mercury model used in Tori's experiment 2116? Will this experiment be the same with other types of mercury?

Hello, the mercury model used in Tori's experiment is 2116, yes, the results will be the same when other types of mercury are used for this experiment.

"Weekend Lab" Issue 3 02 Lecture: Torricelli and the Magdeburg Hemispheric Experiment.

Magdeburg hemispheric experiments have shown that atmospheric pressure is very powerful. In the experiment, the air in the two hemispheres is pumped out, so that the number of air particles in the balls decreases and falls. The atmosphere outside the sphere holds the two hemispheres together, so it is not easy to separate.

The Torricelli experiment measured the magnitude of 1 standard atmosphere.

Experiment Description. 1.Mercury should not be substituted with other liquids, and if it were to be replaced with water, the height would exceed 10 metres and therefore it would not be feasible;

2.If the silver column is full of glass tube and the height is always less than 76cm, it may be that the length of the glass tube is less than 76cm;

3.If the correct measurement is less than the true value, there may be gas in the tube.

4.The results of the experiment (mercury height) were independent of the tube thickness.

This is the understanding of Torricari's experiment:

1. The basis of the experimental understanding is that the principle of the communicator, the principle of the communicator is that the pressure generated by the two ends of the U-tube to the middle part of the low end of the communicator is equal, so as to ensure the balance of the liquid in the U-shaped tube. If the liquid in the U-tube is the same type, then the liquid level at both ends is flat.

2. The experiment is actually a communicator, in which the liquid level at one end is the liquid level of the mercury pool, and the liquid level at the other end is the liquid level of the mercury pipe, there is a feature, the liquid level of the mercury pipe section is sealed, that is to say, there is no air in it, it is vacuum, if we study the low end of the mercury pipe, why does the mercury of this pipe fall, the pressure at this end of the mercury pipe has the pressure generated by the mercury height to the low end, and the pressure on the bottom end of the mercury pool is the pressure of the mercury pool height. But why is the liquid level uneven in the communicator of the same material, this is because there is air in the liquid level, that is, the atmosphere, and another pressure is given to the mercury pool, which is just equal to the pressure and the pressure generated by the mercury pipe, so that the balance is maintained, and the mercury liquid level in the mercury pipe section is high, so the liquid level of the mercury pipe minus the pressure generated by the liquid level height of the mercury pool is the pressure generated by atmospheric pressure, isn't it atmospheric pressure? o(∩_o~

The purpose of this experiment is to measure how long the atmospheric pressure can support the mercury column, and the atmospheric pressure can only support the mercury column of 760mm, and of course it will go down... Atmospheric pressure and mercury pressure are a pair of interacting forces, so they are equal. Theoretically, it will be crushed, but it is a glass tube, there is only a little air pressure difference, and it will not be broken so easily...

This is due to the gravitational pull of the Earth

There are many experiments that can explain the existence of atmospheric pressure, in history, a famous experiment was done in the city square of Magdeburg, Germany, two copper hemispheres were put together, the air inside was extracted, and two horse teams were pulled in opposite directions, and the hemispheres were not pulled apart, thus confirming the existence of atmospheric pressure, and it was the atmospheric pressure that pressed the two hemispheres together, which is the Magdeburg hemisphere experiment that is known as the famous Magdeburg hemisphere experiment;

The Italian scientist Torricelli used liquid mercury to indirectly measure the value of atmospheric pressure, and this experiment used the equilibrium method, that is, the atmospheric pressure is equal to the pressure generated by the mercury column; By calculating the pressure of the mercury column, the value of the atmospheric pressure is obtained

So the answer is: atmospheric pressure; The number of barrages at atmospheric pressure

1, air; Vacuum.

2，76cm；76cm；fall back into the mercury trough; 76cm

1, air; Vacuum.

2）76；76；return to the same height as the external mercury; 76

Process: Fill the sink with mercury and put the glass tube into the mercury, at this time the air in the glass tube is discharged, that is, the mercury is filled with the entire glass tube. Then the glass tube is turned upside down, and there will be a column of water in the glass tube, 760 mm high, at which point the atmospheric pressure can be calculated according to the formula of equilibrium force and pressure p=pgh.

That is to say, the pressure of the outside atmosphere (the atmosphere has pressure everywhere, you should know) on the surface of the mercury in the sink and the pressure of the 760 mm mercury column on the mercury under the glass tube are a pair of balanced forces, and they are equal, so the pressure of the mercury column is found to find the pressure of the atmosphere.

Principle: Equipoise (this point will not be explained in detail in the book, and you don't need to understand it in detail), the liquid pressure formula p=PGH (the pressure of the liquid = the density of the liquid * the fixed value g * the height of the liquid).

According to the formula, you also know that the pressure of the mercury column is only related to its density and height, and the density is needless to say, it is impossible to change.

Height: The height here refers to the straight height of the liquid column and the mercury surface of the sink (i.e., the horizontal plane), whether it is "put like this", "put like this", or "|"."The height of the mercury column will not change.

What happens if the glass tube is less than 760 mm, and the upside-down glass tube is full of mercury; If the glass tube is longer than 760 mm, then the 760 mm mercury column will not fill the entire glass tube, and there is still an empty place at the upper end of the liquid column, which is the vacuum, so the air in the glass tube must be discharged in advance, otherwise there will be air in the vacuum hand, and there will be errors.

If you were to use water to measure the pressure of the atmosphere, how high the water column would be, so Torricelli would experiment with the densest liquid to reduce the height of the liquid column.

The principle is the formula for finding pressure.

It is to put mercury in the slag book tank, put a glass tube in it, measure the length from the mercury surface to the highest point with a ruler is 760mmHg, that is, 760 mm Hg, and then the atmospheric pressure is obtained from the company's p = density * g * h.

PS: Note that the H of the stove is obtained from this test, such as the thickness and length of the macro glass tube and whether the glass tube is inclined or not, it has nothing to do with the size of the atmospheric pressure in this place.