Operating pressure of the fluid.

to deal with the issue of "fluid pressure", start with classic examples and gradually move on to the more complicated and confusing options.For a cylindrical vessel whose walls are strictly vertical, horizontal and bottom, the hydrostatic pressure of the liquid poured to a height h, for each point of the bottom will remain unchanged.The formula for calculating this value will look like p = rgh, where r - the density of the liquid;g - acceleration of free fall;h - height of the liquid column.The value of p for all points of the bottom of the same.

Introducing formula bottom area of ​​the vessel S, one can calculate the pressure force F. Since the fluid pressure on the bottom of the vessel at every point of the same, the logical conclusion come to the formula F = rghS.

easy to notice that in this case the pressure force equal to the weight to the bottom of the liquid poured into the cylindrical vessel proper shape.It looks paradoxical, but has a scientific and logical explanation saying that the formul

a F = rghS works for vessels of very different shapes.In other words, for equal values ​​of S - square bottom and h - the height of the liquid level of the fluid pressure at the bottom of the same for all vessels, regardless of which accommodates the volume of each individual container.The weight of the actual liquid filled into the vessels of any shape can be less or more pressure force to the bottom, but will always satisfy the above rule.

following the basic principles of physics to verify theoretical conclusions into practice, Pascal suggested to use the device, called his own name.The highlight of this device is a special stand, which allows to fix the vessels of different shapes, which do not have a bottom.The bottom of the vessel performs held tightly from the bottom plate, which is located on one arm of the balance beam.

Set the iron weight for a cup of the rocker arm and the other begins to fill the vessel with water.When the fluid pressure will force greater than the weight of the weights, the fluid will open the plate, and it will pour out the excess.By measuring the height of the water column, it is possible to calculate the numerical value of the strength of its pressure on the bottom and compared with the weight of the kettlebell.

Taking into account the possibility for greater pressure forces a small amount of water, only increasing the height level of the water column, it is possible to give an explanation to yet another interesting experience, as described by Pascal.

to the top cover of the new carefully caulked barrel to the brim filled with water, was attached a long tube through which poured water.The tube had a small cross-section, a pair of mugs of water was enough to raise the water column to a considerable height.At some point a new High-quality drum broke and tore at the seams.Regardless of the number of filled liquid, namely water column resulted in an increase in pressure on the bottom of the barrel.The result is a critical amount of force that led to the rupture of the container.

difference between the actual weight of the fluid and the pressure force to the bottom of the vessel due to the offset of force, which causes the fluid pressure at the vessel wall.That inclination of the vessel walls leads to the fact that this pressure is directed either upward or downward, respectively, resulting in the equilibrium system.

vessel having a narrowing upward, feeling the pressure of fluid upward.An interesting experience can be made by preparing a simple installation.It should be fastened to the stationary cylinder piston wear that goes into tube mounted vertically.Gulf water through a tube, seeing as filling the space above the piston of the cylinder leads to lifting up.

To summarize, the concept of "pressure" can be defined as the ratio of the force that acts perpendicular to the surface in relation to its area.The unit is the amount of pressure equal to one Pascal (1 Pa) and the corresponding action of the force of one Newton (1 N) per square meter (1 m).

According to Pascal's law, the pressure experienced by the fluid (gas) is sent unchanged to every point of the volume of the fluid (gas).Proper fluid pressure (gas) is the same at a particular height.It increases with depth.