A lot of the world around us obeys the laws of physics. This should not be surprising, because the term "physics" comes from the Greek word translated "nature". And one of those laws that constantly work around us is Bernoulli's law.
The law itself acts as a consequence of the principle of conservation of energy. Such an interpretation of it allows us to give a new understanding to many previously well-known phenomena. To understand the essence of the law, just remember the leaking stream. Here it flows, runs between stones, branches and roots. In some places it is becoming wider, somewhere narrower. You may notice that where the brook is wider, the water flows more slowly, where already, the water flows faster. This is the Bernoulli principle, which establishes the relationship between the pressure in the fluid flow and the speed of such a flow.
True, physics textbooks formulate it in a slightly different way, and it relates to hydrodynamics, and not to a leaking stream. In a fairly popular form, Bernoulli's law can be stated in this way - the pressure of the fluid flowing in the pipe is higher where its speed is lower, and vice versa: where the speed is higher, the pressure is less.
To confirm, it is enough to conduct a simple experiment. It is necessary to take a sheet of paper and blow along it. The paper will rise up in the direction along which the stream of air passes.
Everything is very simple. As Bernoulli's law says, where the speed is higher, the pressure is less. This means that along the surface of the sheet where the air flow passes , the pressure is less, and below the sheet where there is no air flow, the pressure is greater. Here the leaf rises in the direction where the pressure is less, i.e. where the air flow is.
The described effect is widely used in everyday life and in technology. As an example, you can consider a spray gun or an airbrush. They use two tubes, one larger section, the other smaller. The one with a larger diameter is connected to the container with paint, according to the one with a smaller cross section, air passes with high speed. Due to the resulting pressure difference, the paint enters the air stream and is transferred by this stream to the surface to be painted.
According to the same principle, a pump can also work. In fact, what is described above is a pump.
No less interesting is Bernoulli's law when applied to drain swamps. As always, everything is very simple. Wetlands are connected by ditches to the river. There is a stream in the river, but not in a swamp. Again, a pressure difference occurs, and the river begins to suck out water from the wetlands. A pure demonstration of the work of the law of physics takes place.
The effect of this effect can be destructive. For example, if two ships pass close to each other, then the speed of water between them will be higher than on the other side. As a result, there will be an additional force that will pull the ships to each other, and disaster will be inevitable.
All of the above can be stated in the form of formulas, but Bernoulli's equations are not necessary to write to understand the physical essence of this phenomenon.
For a better understanding, we give another example of the use of the described law. Everyone imagines a rocket. In a special chamber, fuel is burned and a jet stream is formed. To accelerate it, a specially narrowed section is used - the nozzle. Here the acceleration of the gas stream occurs and, as a result, the growth of jet propulsion.
There are still many different options for using Bernoulli's law in technology, but it is simply impossible to consider all of them in the framework of this article.
So, Bernoulli’s law is formulated, an explanation of the physical nature of the processes is given, and examples of the application of this law are shown by examples from nature and technology.