In Pascal s cracked bucket experiment, why does a little water in a high place make the bucket explo

In the experiment, a very thin water pipe was used, and the height of the water was very high, so that the pressure in the bucket was very high, and the bucket was broken due to the pressure.

This is because the pressure of the water is much greater than the atmospheric pressure during deep-water operations.

Wearing a special wetsuit can protect the diver by equalizing the pressure inside and outside the body.

The deeper the water, the greater the pressure, so limit the depth.

Pascal. In 1648 he performed a famous experiment: he used a closed bucket filled with water, inserted a thin pipe into the lid of the bucket, and poured water into the thin pipe from the balcony of the building.

As a result, after only a few glasses of water, the bucket was crushed, and the water in the bucket flowed out of the crack. It turns out that due to the small volume of the thin tube, several cups of water are poured into it, and its depth is very large, which increases the pressure.

big, and the barrel was crushed.

This is known in history as the Pascal Barrel Crack Experiment. The pressure exerted on the bottom (or sidewall) of a container by a liquid is much greater than the gravitational force on the liquid itself, which is inconceivable to many people.

In 1648 Brett Pascal performed an experiment: he used a closed wooden barrel filled with water, inserted a thin pipe into the lid of the barrel, and poured water into the thin pipe from the balcony of the building. As a result, it took only a glass of water to frackard the bucket, and the water in the bucket flowed out of the crack.

It turned out that due to the small volume of the thin pipe, several cups of water were poured into it, and its depth was very large, which increased the pressure, and the barrel was fractured.

Because the pressure of the liquid is equal to the density, depth, and acceleration due to gravity.

The product of constants. In this experiment, the density of the water remains the same, but the depth increases repeatedly, the pressure in the lower part increases, and the hydraulic pressure finally exceeds the upper limit of what the barrel can bear, and the barrel cracks.

Pascal's "barrel cracking" experiment is a good demonstration of liquid pressure.

It has nothing to do with the depth of the liquid, but not the mass of the liquid and the shape of the container.

P= ghp pressure (unit: Pa).

The density of the liquid (unit: kg m).

g = under special instructions = 10 n kg).

h Depth (unit: m).

Note: The units cannot be mistaken when calculating!

Because the higher the altitude, the lower the air pressure, and of course putting a little water will make the bucket burst.

The higher it is, the greater the gravity, the faster the speed, and the higher the damage.

The pressure is much higher than the gravity itself, so a little water is enough for the bucket to be secured.

The strength of the water itself also increases as it descends, and it can cause great damage to small buckets

The pressure exerted on the bottom (or sidewall) of a container by the liquid is much greater than the gravitational force exerted on the liquid itself.

Because the gravitational potential energy of the liquid at high places is high, the pressure on the barrel is also great.

The increased pressure of the water on the container can cause the bucket to burst.

The higher the height, the greater the gravitational potential energy and the greater the force received.

In the air, the volume of water increases due to the increase in pressure.

This is the same as jumping down from the first floor and jumping down from the eighth floor, the higher the height, the greater the power.

Because the pressure of the liquid is equal to the product of the density, depth, and gravitational acceleration constant. In this experiment, the density of the water remains the same, but the depth increases repeatedly, the pressure in the lower part increases, while the stressed area (the inner surface area of the barrel) does not change, and the pressure is equal to the pressure divided by the stressed area, then the pressure becomes greater and larger, and finally exceeds the upper limit that the barrel can bear, and then splits.

In 1648, the famous French physicist Pascal experimented with water and wine in Paris, and after filling a 12-meter-long tube with water, he burst a sturdy new wooden barrel

Pascal's "barrel cracking" experiment is a good example of how liquid pressure is related to the depth of the liquid.

After pouring a few cups of water, although the quality of the water changes, because it is a thin tube, so after pouring a few cups of water, the depth of the water in the thin tube increases a lot, according to the characteristics of the liquid pressure, it can be seen that the liquid pressure increases with the increase of depth, so this experiment shows that the factor affecting the internal pressure of the liquid is the depth of the liquid

So the answer is: b

In the experiment, a very thin water pipe was used, and the height of the water was very high, so that the pressure in the bucket was very high, and the bucket was broken due to the pressure.

This is because the pressure of the water is much greater than the atmospheric pressure during deep-water operations. Wearing a special wetsuit can protect the diver by equalizing the pressure inside and outside the front.

The deeper the mercury is blind, the greater the pressure, so the depth should be limited.

In the Pascal cracked barrel experiment, the impulse of the thin stream of water was insignificant.

1) The mass of the water flow is very small, and the water is injected gradually, and the mass m of each small column of water is even smaller.

2) The liquid level of water in the thin tube rises gradually, and the height of each section of the water column is very small, which is not enough to produce a large falling velocity v.

3) The collision time of the water column after falling to the water surface in the water pipe at velocity v is not extremely short (equivalent to falling on the sponge pad, the collision time t is very long).

Combining the above three items, it can be seen from the impulse force f=m(v-0) t that f is extremely small.

During the experiment, you can first put the thin tube down to fill it with water, and then stand it up to observe the phenomenon. This will reassure you.

The Pascal crack barrel experiment demonstrates the phenomenon of "all-round conduction of hydraulic pressure". The pressure is generated by the liquid column in the thin glass tube, and the higher the height, the greater the pressure. It has nothing to do with the thickness of the glass tube.

This is like a manual pump pumping a bicycle tire, regardless of the thickness of the valve needle, only the gas pressure. The lever piston pump of the hydraulic jack is small, and the oil pipe (built-in oil hole) is small, which can still lift a large truck. The principle is the same.

The speed of the water cup flushing is similar to the movement speed of the piston of the gas cylinder and the movement speed of the manual lever of the hydraulic jack to give the bicycle atmosphere, and the influence on the fluid pressure can be ignored.

Pascal's cracked barrel experiment is caused by the dynamic pressure of the liquid, not the impulse of the hydraulic pressure that causes the cracking of the barrel. The effect of the impulse on the cracking barrel is almost negligible.

The pressure caused by hydraulics is very strong. So Jiaolong can dive to a depth of more than 6,000 meters, which is really good.

The height of the experimental device is too high to be demonstrated in the classroom, and it can inspire students to think: Can all the devices be scaled down accordingly? The answer is no, and then ask again:

The length of the tube is reduced, the pressure of the liquid is reduced, and the pressure of the liquid on the barrel must be reduced; Although the barrel is smaller, its pressure resistance is almost unchanged, and it is impossible for the barrel to crack, so can other objects be used to simulate the "cracked barrel"? Students naturally think of using an object with lower pressure resistance (such as a thin plastic bag) to understand the essence of liquid pressure when comparing a plastic bag filled with water under the action of a glass of water and a tube of water of the same mass

Take a large jar (about 30 cm in diameter and 40 cm in height) that is used to measure the pressure of liquids, tie it tightly with rubber film at the nozzle of the side wall at the bottom of the bottle, pour red water from the mouth of the bottle, and as the water level in the bottle rises, the rubber film of the side tube gradually bulges out, and it can be seen that even after filling with water, the degree of film bulging out is not very obvious (Fig. 1).This means that although the bottle contains a lot of heavy water, the pressure on the side wall is not very large. Take a 1-metre-long Torricelli glass tube and insert it into the large bottle through a stopper with a small hole, and seal the stopper tightly.

When a student was asked to stand on a stool and gradually pour the water from the beaker into the tube with a funnel (Fig. 2), when the red water in the glass tube rose by more than 50 cm, the rubber film on the side tube of the large bottle bulged out vividly.