There are various types of movement in the world as a way of moving bodies from one point in space to another. in nature and technology, which occurs when a part of it is separated from the body at any speed, is certainly less common, but still occupies its rightful place. And in technology, scientists actually “spied” jet propulsion from living nature. And they used it quite successfully in their inventions. Our material will tell you about this and much more, no less interesting.

Reactivity in animals

For example, swimming in sea ​​wave, many people often came face to face with representatives aquatic fauna- jellyfish. But few people thought that these animals use a reactive type for movement. Also, marine plankton and the larvae of some insect species move using reactivity. And, by the way, in technology, jet propulsion, or rather its efficiency, is sometimes much lower than that of these creations of nature.

Many shellfish also use it. And they move, for example, due to the reactivity of the stream of water released from the animal’s shell when the valves are compressed. The squid still has something skillfully developed by nature. Due to this, there is a sharp movement of it into aquatic environment and sometimes this one sea ​​creature It even flies into the air!

Jet propulsion in technology. Examples

This method is also widely used in the modern era. It should be noted that in technology, reactive movement largely copies natural reactivity. Even in ancient times in China (first millennium AD), bamboo pipes filled with gunpowder were invented, which were used mainly for fun. They were based on the reactive principle. And Newton at one time came up with not only the same name but also the prototype of a car that was equipped with a jet engine.

For human flight

People realized that jet propulsion could be used in technology for flight. The first author of such a project is considered to be the Narodnaya Volya member Kibalchich, who literally a few days before his death (he was sentenced to death as a participant in the assassination attempt on the Tsar) developed and recorded scientific data. Tsiolkovsky developed Kibalchich’s ideas and developed a mathematical equation that was important for astronautics, allowing the use of the reactivity principle. It was he who described in his works the principles of operation of jet units using liquid fuel.

Jet engine

In its design, it converts fuel chemical energy into kinetic energy - already a gas jet. In this case, the speed of the reverse direction is acquired. Tsiolkovsky's ideas were developed by Korolev, and the launch of the first satellite using it was carried out in 1957 in the USSR. And the first person to overcome gravity with the help of jet propulsion was the Soviet pilot Gagarin in 1961. He flew around the planet on the Vostok spacecraft.

Rocket device

To put it simply, a modern launch vehicle consists of a shell and fuel (plus an oxidizer). The shell contains a payload - a space capsule, which is launched into Earth orbit. Control devices and the engine are also located here. The rest of the useful area of ​​the rocket is occupied by fuel and an oxidizer designed to support the combustion process (after all, there is no oxygen in space).

In the combustion chamber, the fuel is converted into gas under high pressure and very high temperatures. Due to the difference in pressure outside the spacecraft and in the combustion chambers, the gas rushes out, due to which the rocket moves.

This turntable can be called the world's first steam jet turbine.

Chinese rocket

Even earlier, many years before Heron of Alexandria, China also invented jet engine a slightly different device, now called fireworks rocket. Fireworks rockets should not be confused with their namesakes - signal rockets, which are used in the army and navy, and are also launched on national holidays under the roar of artillery fireworks. Flares are simply bullets compressed from a substance that burns with a colored flame. They are fired from large-caliber pistols - rocket launchers.

Flares are bullets compressed from a substance that burns with a colored flame.

Chinese rocket is a cardboard or metal tube, closed at one end and filled with powder composition. When this mixture is ignited, a stream of gases escapes from high speed from the open end of the tube, causes the rocket to fly in the direction opposite to the direction of the gas stream. Such a rocket can take off without the help of a rocket launcher. A stick tied to the rocket body makes its flight more stable and straight.

Fireworks using Chinese rockets

Sea inhabitants

In the animal world:

Jet propulsion is also found here. Cuttlefish, octopuses and some other cephalopods have neither fins nor a powerful tail, but swim no worse than others sea ​​inhabitants. These soft-bodied creatures have a fairly capacious sac or cavity in their body. Water is drawn into the cavity, and then the animal with great strength pushes this water out. The reaction of the ejected water causes the animal to swim in the direction opposite to the direction of the stream.

The octopus is a sea creature that uses jet propulsion

Falling cat

But the most interesting way the movements were demonstrated by an ordinary cat.

About a hundred and fifty years ago, a famous French physicist Marcel Depres stated:

But you know, Newton's laws are not entirely true. The body can move with the help of internal forces, without relying on anything or pushing away from anything.

Where is the evidence, where are the examples? - the listeners protested.

Want proof? If you please. A cat accidentally falling off a roof is proof! No matter how the cat falls, even head down, it will definitely stand on the ground with all four paws. But a falling cat does not rely on anything and does not push away from anything, but turns over quickly and deftly. (Air resistance can be neglected - it is too insignificant.)

Indeed, everyone knows this: cats, falling; always manage to get back on their feet.

Cats do this instinctively, but humans can do the same consciously. Swimmers who jump from a platform into the water know how to perform a complex figure - a triple somersault, that is, turn over three times in the air, and then suddenly straighten up, stop the rotation of their body and dive into the water in a straight line.

The same movements, without interaction with any foreign object, happen to be observed in the circus during the performance of acrobats - aerial gymnasts.

Performance of acrobats - aerial gymnasts

The falling cat was photographed with a film camera and then on the screen they examined, frame by frame, what the cat does when it flies in the air. It turned out that the cat was quickly twirling its paw. The rotation of the paw causes a response movement of the entire body, and it turns in the direction opposite to the movement of the paw. Everything happens in strict accordance with Newton's laws, and it is thanks to them that the cat gets on its feet.

The same thing happens in all cases when living creature changes its movement in the air for no apparent reason.

Jet boat

The inventors had an idea, why not adopt their swimming method from cuttlefish. They decided to build a self-propelled ship with jet engine. The idea is definitely feasible. True, there was no confidence in success: the inventors doubted whether such a thing would turn out jet boat better than a regular screw. It was necessary to do an experiment.

Jet boat - a self-propelled vessel with a jet engine

They selected an old tug steamer, repaired its hull, removed the propellers, and installed a water jet pump in the engine room. This pump pumped seawater and through a pipe pushed it behind the stern with a strong jet. The steamer floated, but it still moved slower than the screw steamer. And this can be explained simply: an ordinary propeller rotates behind the stern, unconstrained, with only water around it; The water in the water-jet pump was driven by almost exactly the same screw, but it no longer rotated on the water, but in a tight pipe. Friction of the water jet against the walls occurred. Friction weakened the pressure of the jet. A steamship with a water-jet propulsion sailed slower than a screw-propelled one and consumed more fuel.

However, they did not abandon the construction of such steamers: they had important advantages. A boat equipped with a propeller must sit deep in the water, otherwise the propeller will uselessly foam the water or spin in the air. Therefore, screw steamers are afraid of shallows and riffles; they cannot sail in shallow water. And water-jet steamers can be built shallow-draft and flat-bottomed: they don’t need depth - where the boat goes, the water-jet steamer will go.

The first water-jet boats in the Soviet Union were built in 1953 at the Krasnoyarsk shipyard. They are designed for small rivers where ordinary steamboats cannot navigate.

Engineers, inventors and scientists began to study jet propulsion especially diligently when firearms . The first guns - all kinds of pistols, muskets and self-propelled guns - hit a person hard in the shoulder with each shot. After several dozen shots, the shoulder began to hurt so much that the soldier could no longer aim. The first cannons - squeaks, unicorns, culverins and bombards - jumped back when fired, so that it happened that the gunners-artillerymen were crippled if they did not have time to dodge and jump to the side.

The gun's recoil interfered with accurate shooting because the gun flinched before the cannonball or grenade left the barrel. This threw off the lead. The shooting turned out to be aimless.

Shooting with firearms

Ordnance engineers began combating recoil more than four hundred and fifty years ago. First, the carriage was equipped with a coulter, which crashed into the ground and served as a strong support for the gun. Then they thought that if the gun was properly supported from behind, so that there was nowhere for it to roll away, then the recoil would disappear. But it was a mistake. The law of conservation of momentum was not taken into account. The guns broke all the supports, and the carriages became so loose that the gun became unsuitable for combat work. Then the inventors realized that the laws of motion, like any laws of nature, cannot be remade in their own way, they can only be “outwitted” with the help of science - mechanics.

They left a relatively small opener at the carriage for support, and placed the cannon barrel on a “sled” so that only one barrel rolled away, and not the entire gun. The barrel was connected to a compressor piston, which moves in its cylinder in the same way as a steam engine piston. But in the cylinder of a steam engine there is steam, and in a gun compressor there is oil and a spring (or compressed air).

When the gun barrel rolls back, the piston compresses the spring. At this time, the oil is forced through small holes in the piston on the other side of the piston. Strong friction arises, which partially absorbs the movement of the rolling barrel, making it slower and smoother. Then the compressed spring straightens and returns the piston, and with it the gun barrel, to its original place. The oil presses on the valve, opens it and flows freely back under the piston. During rapid fire, the gun barrel moves almost continuously back and forth.

In a gun compressor, recoil is absorbed by friction.

Muzzle brake

When the power and range of the guns increased, the compressor was not enough to neutralize the recoil. It was invented to help him muzzle brake.

The muzzle brake is just a short steel pipe mounted on the end of the barrel and serves as its continuation. Its diameter is larger than the diameter of the barrel, and therefore it does not in the least interfere with the projectile flying out of the barrel. Several oblong holes are cut around the circumference of the tube walls.

Muzzle brake - reduces firearm recoil

Powder gases flying out of the gun barrel following the projectile immediately diverge to the sides, and some of them fall into the holes of the muzzle brake. These gases hit the walls of the holes with great force, are repelled from them and fly out, but not forward, but slightly askew and backward. At the same time, they press forward on the walls and push them, and with them the entire barrel of the gun. They help the fire monitor because they tend to cause the barrel to roll forward. And while they were in the barrel, they pushed the gun back. The muzzle brake significantly reduces and dampens recoil.

Other inventors took a different route. Instead of fighting reactive movement of the barrel and try to extinguish it, they decided to use the gun's rollback to good effect. These inventors created many types of automatic weapons: rifles, pistols, machine guns and cannons, in which the recoil serves to eject the spent cartridge case and reload the weapon.

Rocket artillery

You don’t have to fight recoil at all, but use it: after all, action and reaction (recoil) are equivalent, equal in rights, equal in magnitude, so let reactive action of powder gases, instead of pushing the gun barrel back, sends the projectile forward towards the target. This is how it was created rocket artillery . In it, a stream of gases hits not forward, but backward, creating a forward-directed reaction in the projectile.

For rocket gun the expensive and heavy barrel turns out to be unnecessary. A cheaper, simple iron pipe works perfectly to direct the flight of the projectile. You can do without a pipe at all, and make the projectile slide along two metal slats.

In its design, a rocket projectile is similar to a fireworks rocket, it is only larger in size. In its head part, instead of the composition for color sparkler a large explosive charge is placed destructive force. The middle of the projectile is filled with gunpowder, which, when burned, creates a powerful stream of hot gases that pushes the projectile forward. In this case, the combustion of gunpowder can last a significant part of the flight time, and not just the short period of time while an ordinary projectile advances in the barrel of an ordinary gun. The shot is not accompanied by such a loud sound.

Rocket artillery is no younger than ordinary artillery, and maybe even older than it: o combat use rockets are reported by ancient Chinese and Arabic books written more than a thousand years ago.

In descriptions of battles of later times, no, no, and there will be a mention of combat missiles. When British troops conquered India, Indian rocket warriors, with their fire-tailed arrows, terrified the British invaders who enslaved their homeland. For the British at that time rocket weapons it was a novelty.

Rocket grenades invented by the general K. I. Konstantinov, the courageous defenders of Sevastopol in 1854-1855 repelled the attacks of the Anglo-French troops.

Rocket

The huge advantage over conventional artillery - there was no need to carry heavy guns - attracted the attention of military leaders to rocket artillery. But an equally major drawback prevented its improvement.

The fact is that the propelling charge, or, as they used to say, the force charge, could only be made from black powder. And black powder is dangerous to handle. It happened that during production missiles the propellant exploded and the workers died. Sometimes the rocket exploded upon launch, killing the gunners. Making and using such weapons was dangerous. That's why it hasn't become widespread.

The work that began successfully, however, did not lead to the construction of an interplanetary spacecraft. The German fascists prepared and unleashed a bloody world war.

Missile

The shortcomings in the production of rockets were eliminated by Soviet designers and inventors. During the Great Patriotic War they gave our army excellent rocket weapons. Guards mortars were built - "Katyusha" and RS ("eres") were invented - rockets.

Missile

In terms of quality, Soviet rocket artillery surpassed all foreign models and caused enormous damage to enemies.

Defending the Motherland, the Soviet people were forced to put all the achievements of rocket technology into the service of defense.

In fascist states, many scientists and engineers, even before the war, were intensively developing projects for inhumane weapons of destruction and mass murder. This they considered the purpose of science.

Self-driving aircraft

During the war, Hitler's engineers built several hundred self-driving aircraft: FAU-1 shells and rockets"FAU-2". These were cigar-shaped shells, 14 meters long and 165 centimeters in diameter. The deadly cigar weighed 12 tons; of which 9 tons are fuel, 2 tons are casing and 1 ton are explosives. "V-2" flew at speeds of up to 5,500 kilometers per hour and could rise to a height of 170-180 kilometers.

These means of destruction did not differ in hit accuracy and were only suitable for firing at such large targets as large and densely populated cities. The German fascists produced the V-2 200-300 kilometers from London in the belief that the city was large - it would hit somewhere!

It is unlikely that Newton could have imagined that his witty experience and the laws of motion he discovered would form the basis of weapons created by bestial anger towards people, and entire blocks of London would turn into ruins and become the graves of people captured by the raid of the blind “FAU”.

Spacecraft

For many centuries, people have cherished the dream of flying in interplanetary space, of visiting the Moon, mysterious Mars and cloudy Venus. Many science fiction novels, novellas and short stories have been written on this topic. Writers sent their heroes to the sky on trained swans, balloons, in cannon shells or in some other incredible way. However, all these methods of flight were based on inventions that had no support in science. People only believed that they would someday be able to leave our planet, but did not know how they would be able to do this.

Wonderful scientist Konstantin Eduardovich Tsiolkovsky in 1903 for the first time gave a scientific basis to the idea space travel . He proved that people can leave globe and the vehicle for this will be a rocket, because a rocket is the only engine that does not need any external support for its movement. That's why rocket capable of flying in airless space.

Scientist Konstantin Eduardovich Tsiolkovsky proved that people can leave the globe on a rocket

In terms of its structure, the spacecraft should be similar missile, only in its head part will there be a cabin for passengers and instruments, and the rest of the space will be occupied by the fuel supply and the engine.

To give the ship the required speed, the right fuel is required. Gunpowder and other explosives are by no means suitable: they are both dangerous and burn too quickly, not providing long-term movement. K. E. Tsiolkovsky recommended using liquid fuel: alcohol, gasoline or liquefied hydrogen, burning in a stream of pure oxygen or some other oxidizer. Everyone recognized the correctness of this advice, because they did not know the best fuel at that time.

The first rocket with liquid fuel, weighing sixteen kilograms, was tested in Germany on April 10, 1929. The experimental rocket took off into the air and disappeared from view before the inventor and everyone present were able to trace where it flew. It was not possible to find the rocket after the experiment. The next time, the inventor decided to “outwit” the rocket and tied a rope four kilometers long to it. The rocket took off, dragging its rope tail behind it. She pulled out two kilometers of rope, broke it and followed her predecessor in an unknown direction. And this fugitive also could not be found.

Jet propulsion in nature and technology

ABSTRACT ON PHYSICS

Jet propulsion- movement that occurs when any part of it is separated from the body at a certain speed.

Reactive force occurs without any interaction with external bodies.

Application of jet propulsion in nature

Many of us in our lives have encountered jellyfish while swimming in the sea. In any case, there are quite enough of them in the Black Sea. But few people thought that jellyfish also use jet propulsion to move. In addition, this is how dragonfly larvae and some species of marine plankton move. And often the efficiency of marine invertebrate animals when using jet propulsion is much higher than that of technological inventions.

Jet propulsion is used by many mollusks - octopuses, squids, cuttlefish. For example, a sea scallop mollusk moves forward due to the reactive force of a stream of water thrown out of the shell during a sharp compression of its valves.

Octopus

Cuttlefish

Cuttlefish, like most cephalopods, moves in water in the following way. She takes water into the gill cavity through a side slit and a special funnel in front of the body, and then energetically throws out a stream of water through the funnel. The cuttlefish directs the funnel tube to the side or back and, rapidly squeezing water out of it, can move in different sides.

The salpa is a marine animal with a transparent body; when moving, it receives water through the front opening, and the water enters a wide cavity, inside of which the gills are stretched diagonally. As soon as the animal takes a large sip of water, the hole closes. Then the longitudinal and transverse muscles of the salp contract, the whole body contracts, and water is pushed out through the posterior opening. The reaction of the escaping jet pushes the salpa forward.

The squid's jet engine is of greatest interest. The squid is the largest invertebrate inhabitant ocean depths. Squids have achieved the highest perfection in jet navigation. They even have their own bodies external forms copies the rocket (or better said, the rocket copies the squid, since it has indisputable priority in this matter). When moving slowly, the squid uses a large diamond-shaped fin that periodically bends. It uses a jet engine to throw quickly. Muscle tissue - the mantle surrounds the mollusk's body on all sides; the volume of its cavity is almost half the volume of the squid's body. The animal sucks water inside the mantle cavity, and then sharply throws out a stream of water through a narrow nozzle and moves backwards with high speed pushes. At the same time, all ten tentacles of the squid are gathered into a knot above its head, and it takes on a streamlined shape. The nozzle is equipped with a special valve, and the muscles can rotate it, changing the direction of movement. The squid's engine is very economical, it is capable of reaching speeds of up to 60 - 70 km/h. (Some researchers believe that even up to 150 km/h!) No wonder the squid is called a “living torpedo.” By bending the bundled tentacles to the right, left, up or down, the squid turns in one direction or another. Since such a steering wheel, compared to the animal itself, has a very large sizes, then its slight movement is enough for the squid, even at full speed ahead, could easily dodge a collision with an obstacle. A sharp turn of the steering wheel - and the swimmer rushes into reverse side. So he bent the end of the funnel back and now slides head first. He bent it to the right - and the jet push threw him to the left. But when you need to swim quickly, the funnel always sticks out right between the tentacles, and the squid rushes tail first, just as a crayfish would run - a fast walker endowed with the agility of a horse.

If there is no need to rush, squids and cuttlefish swim, undulating their fins - miniature waves run over them from front to back, and the animal glides gracefully, occasionally pushing itself also with a stream of water thrown out from under the mantle. Then the individual shocks that the mollusk receives at the moment of eruption of water jets are clearly visible. Some cephalopods can reach speeds of up to fifty-five kilometers per hour. It seems that no one has made direct measurements, but this can be judged by the speed and flight range of flying squids. And it turns out that octopuses have such talents in their family! The best pilot among mollusks is the squid Stenoteuthis. English sailors call it flying squid (“flying squid”). This is a small animal about the size of a herring. It chases fish with such speed that it often jumps out of the water, skimming over its surface like an arrow. He resorts to this trick to save his life from predators - tuna and mackerel. Having developed maximum jet thrust in the water, the pilot squid takes off into the air and flies over the waves for more than fifty meters. The apogee of a living rocket's flight lies so high above the water that flying squids often end up on the decks of ocean-going ships. Four to five meters is not a record height to which squids rise into the sky. Sometimes they fly even higher.

The English mollusk researcher Dr. Rees described in a scientific article a squid (only 16 centimeters long), which, having flown a fair distance through the air, fell on the bridge of a yacht, which rose almost seven meters above the water.

It happens that a lot of flying squids fall on the ship in a sparkling cascade. The ancient writer Trebius Niger once told a sad story about a ship that allegedly sank under the weight of flying squids that fell on its deck. Squids can take off without acceleration.

Octopuses can also fly. French naturalist Jean Verani saw how an ordinary octopus accelerated in an aquarium and suddenly jumped out of the water backwards. Having described an arc about five meters long in the air, he plopped back into the aquarium. When picking up speed to jump, the octopus moved not only due to jet thrust, but also rowed with its tentacles.
Baggy octopuses swim, of course, worse than squids, but at critical moments they can show a record class for the best sprinters. California Aquarium staff tried to photograph an octopus attacking a crab. The octopus rushed at its prey with such speed that the film, even when filming at the highest speeds, always contained grease. This means that the throw lasted hundredths of a second! Typically, octopuses swim relatively slowly. Joseph Seinl, who studied the migrations of octopuses, calculated: an octopus half a meter in size swims in the sea with average speed about fifteen kilometers per hour. Each jet of water thrown out of the funnel pushes it forward (or rather, backward, since the octopus swims backwards) two to two and a half meters.

Jet motion can also be found in the plant world. For example, the ripened fruits of the “mad cucumber”, with the slightest touch, bounce off the stalk, and a sticky liquid with seeds is forcefully thrown out of the resulting hole. The cucumber itself flies off into opposite direction up to 12 m.

Knowing the law of conservation of momentum, you can change your own speed of movement in open space. If you are in a boat and you have several heavy stones, then throwing stones in a certain direction will move you in the opposite direction. The same will happen in outer space, but they use jet engines for this.

Everyone knows that a shot from a gun is accompanied by recoil. If the weight of the bullet were equal to the weight of the gun, they would fly apart at the same speed. Recoil occurs because the ejected mass of gases creates a reactive force, thanks to which movement can be ensured both in air and in airless space. And the greater the mass and speed of the flowing gases, the greater the recoil force our shoulder feels, the stronger the reaction of the gun, the greater the reactive force.

Application of jet propulsion in technology

For many centuries, humanity has dreamed of space flight. Science fiction writers have proposed a variety of means to achieve this goal. In the 17th century, a story by the French writer Cyrano de Bergerac about a flight to the moon appeared. The hero of this story reached the Moon in an iron cart, over which he constantly threw a strong magnet. Attracted to him, the cart rose higher and higher above the Earth until it reached the Moon. And Baron Munchausen said that he climbed to the moon along a bean stalk.

At the end of the first millennium AD, China invented jet propulsion, which powered rockets - bamboo tubes filled with gunpowder, they were also used as fun. One of the first car projects was also with a jet engine and this project belonged to Newton

The author of the world's first project of a jet aircraft intended for human flight was the Russian revolutionary N.I. Kibalchich. He was executed on April 3, 1881 for his participation in the assassination attempt on Emperor Alexander II. He developed his project in prison after being sentenced to death. Kibalchich wrote: “While in prison, a few days before my death, I am writing this project. I believe in the feasibility of my idea, and this faith supports me in my terrible situation... I will calmly face death, knowing that my idea will not die with me.”

The idea of ​​using rockets for space flights was proposed at the beginning of this century by the Russian scientist Konstantin Eduardovich Tsiolkovsky. In 1903, an article by Kaluga gymnasium teacher K.E. appeared in print. Tsiolkovsky “Exploration of world spaces using reactive instruments.” This work contained the most important mathematical equation for astronautics, now known as the “Tsiolkovsky formula,” which described the motion of a body of variable mass. Subsequently, he developed a rocket engine design based on liquid fuel, proposed a multi-stage rocket design, expressed the idea of ​​​​the possibility of creating entire space cities in low-Earth orbit. He showed that the only device capable of overcoming gravity is a rocket, i.e. a device with a jet engine that uses fuel and oxidizer located on the device itself.

Jet engine is an engine that converts the chemical energy of fuel into kinetic energy gas jet, while the engine acquires speed in the opposite direction.

The idea of ​​K.E. Tsiolkovsky was implemented by Soviet scientists under the leadership of Academician Sergei Pavlovich Korolev. The first artificial Earth satellite in history was launched by rocket in the Soviet Union on October 4, 1957.

The principle of jet propulsion is widely used practical application in aviation and astronautics. There is no medium in outer space with which a body could interact and thereby change the direction and magnitude of its speed, therefore for space flights only reactive ones can be used aircraft, i.e. rockets.

Rocket device

The motion of a rocket is based on the law of conservation of momentum. If at some point in time any body is thrown away from the rocket, it will acquire the same impulse, but directed in the opposite direction

Any rocket, regardless of its design, always has a shell and fuel with an oxidizer. The rocket shell includes the payload (in this case the spacecraft), the instrument compartment and the engine (combustion chamber, pumps, etc.).

The main mass of the rocket is fuel with an oxidizer (the oxidizer is needed to maintain fuel combustion, since there is no oxygen in space).

Fuel and oxidizer are supplied to the combustion chamber using pumps. Fuel, when burned, turns into gas high temperature And high pressure. Due to the large pressure difference in the combustion chamber and in outer space, gases from the combustion chamber rush out through the bell in a powerful jet special form, called a nozzle. The purpose of the nozzle is to increase the speed of the jet.

Before the rocket launches, its momentum is zero. As a result of the interaction of the gas in the combustion chamber and all other parts of the rocket, the gas escaping through the nozzle receives some impulse. Then the rocket is a closed system, and its total momentum must be zero after launch. Therefore, the entire shell of the rocket that is in it receives an impulse equal in magnitude to the impulse of the gas, but opposite in direction.

The most massive part of the rocket, intended for launch and acceleration of the entire rocket, is called the first stage. When the first massive step multistage rocket exhausts all fuel reserves during acceleration, it separates. Further acceleration is continued by the second, less massive stage, and it adds some more speed to the speed previously achieved with the help of the first stage, and then separates. The third stage continues to increase speed to the required value and delivers the payload into orbit.

The first person to fly in outer space was a citizen of the Soviet Union, Yuri Alekseevich Gagarin. April 12, 1961 He circled the globe on the Vostok satellite.

Soviet rockets were the first to reach the Moon, circled the Moon and photographed its side invisible from Earth, and were the first to reach the planet Venus and deliver scientific instruments to its surface. In 1986, two Soviet spacecraft, Vega 1 and Vega 2, closely examined Halley's Comet, which approaches the Sun once every 76 years.

The logic of nature is the most accessible and most useful logic for children.

Konstantin Dmitrievich Ushinsky(03.03.1823–03.01.1871) - Russian teacher, founder of scientific pedagogy in Russia.

BIOPHYSICS: JET MOTION IN LIVING NATURE

I invite readers of the green pages to look into fascinating world biophysicists and get to know the main principles of jet propulsion in wildlife. Today on the program: jellyfish cornermouth- the largest jellyfish in the Black Sea, scallops, enterprising rocker dragonfly larva, amazing the squid with its unrivaled jet engine and wonderful illustrations performed by a Soviet biologist and animal artist Kondakov Nikolai Nikolaevich.

A number of animals move in nature using the principle of jet propulsion, for example, jellyfish, scallops, dragonfly larvae, squid, octopus, cuttlefish... Let's get to know some of them better ;-)

The jet method of movement of jellyfish

Jellyfish are one of the most ancient and numerous predators on our planet! The body of a jellyfish is 98% water and is largely composed of hydrated connective tissue - mesoglea functioning like a skeleton. The basis of mesoglea is the protein collagen. The gelatinous and transparent body of the jellyfish is shaped like a bell or an umbrella (a few millimeters in diameter up to 2.5 m). Most jellyfish move in a reactive way, pushing water out of the umbrella cavity.

Jellyfish Cornerata(Rhizostomae), order of coelenterate animals of the scyphoid class. Jellyfish ( up to 65 cm in diameter) lacking marginal tentacles. The edges of the mouth are elongated into oral lobes with numerous folds that grow together to form many secondary oral openings. Touching the mouth blades may cause painful burns caused by the action of stinging cells. About 80 species; They live mainly in tropical, less often in temperate seas. In Russia - 2 types: Rhizostoma pulmo common in Black and Seas of Azov, Rhopilema asamushi found in the Sea of ​​Japan.

Jet escape of sea clams scallops

Shellfish scallops, usually lying calmly on the bottom, when their main enemy approaches them - a delightfully slow, but extremely insidious predator - starfish- they sharply squeeze the doors of their sink, forcefully pushing water out of it. Thus using jet propulsion principle, they emerge and, continuing to open and close the shell, can swim a considerable distance. If for some reason the scallop does not have time to escape with its jet flight, starfish wraps her arms around it, opens the shell and eats it...

Sea Scallop(Pecten), a genus of marine invertebrates of the class bivalves(Bivalvia). The scallop shell is rounded with a straight hinge edge. Its surface is covered with radial ribs diverging from the top. The shell valves are closed by one strong muscle. Pecten maximus, Flexopecten glaber live in the Black Sea; in the Seas of Japan and Okhotsk – Mizuhopecten yessoensis ( up to 17 cm in diameter).

Rocker dragonfly larva jet pump

Temperament Rocker dragonfly larvae, or eshny(Aeshna sp.) is no less predatory than its winged relatives. She lives for two and sometimes four years in the underwater kingdom, crawling along the rocky bottom, tracking down small aquatic inhabitants, happily including fairly large-sized tadpoles and fry in her diet. In moments of danger, the larva of the rocker dragonfly takes off and swims forward with jerks, driven by the work of the remarkable jet pump. Taking water into the hindgut and then abruptly throwing it out, the larva jumps forward, driven by the recoil force. Thus using jet propulsion principle, the larva of the rocker dragonfly with confident jerks and jerks hides from the threat pursuing it.

Reactive impulses of the nervous “freeway” of squids

In all the above cases (principles of jet propulsion of jellyfish, scallops, rocker dragonfly larvae), shocks and jerks are separated from each other by significant periods of time, therefore high speed of movement is not achieved. To increase the speed of movement, in other words, number of reactive impulses per unit time, necessary increased nerve conduction which stimulate muscle contraction, servicing a living jet engine. Such large conductivity is possible with a large nerve diameter.

It is known that Squids have the largest nerve fibers in the animal world. On average, they reach a diameter of 1 mm - 50 times larger than that of most mammals - and they conduct excitation at a speed 25 m/s. And a three-meter squid dosidicus(it lives off the coast of Chile) the thickness of the nerves is fantastically large - 18 mm. Nerves are thick like ropes! Brain signals - the exciters of contractions - rush along the squid's nervous "freeway" at the speed of a car - 90 km/h.

Thanks to squids, research into the vital functions of nerves advanced rapidly at the beginning of the 20th century. "And who knows, writes British naturalist Frank Lane, maybe there are people now who owe the squid the fact that they nervous system is in good condition..."

The speed and maneuverability of the squid is also explained by its excellent hydrodynamic forms animal body, why squid and nicknamed “living torpedo”.

Squid(Teuthoidea), suborder of cephalopods of the order Decapods. The size is usually 0.25-0.5 m, but some species are largest invertebrate animals(squids of the genus Architeuthis reach 18 m, including the length of the tentacles).
The body of squids is elongated, pointed at the back, torpedo-shaped, which determines their high speed of movement as in water ( up to 70 km/h), and in the air (squids can jump out of the water to a height up to 7 m).

Squid Jet Engine

Jet propulsion, now used in torpedoes, aircraft, missiles and space shells, is also characteristic of cephalopods - octopuses, cuttlefish, squids. Of greatest interest to technicians and biophysicists is squid jet engine. Notice how simply, with what minimal use of material, nature solved this complex and still unsurpassed task;-)

In essence, the squid has two fundamentally different engines ( rice. 1a). When moving slowly, it uses a large diamond-shaped fin, which periodically bends in the form of a running wave along the body of the body. The squid uses a jet engine to launch itself quickly.. The basis of this engine is the mantle - muscle tissue. It surrounds the mollusk’s body on all sides, making up almost half the volume of its body, and forms a kind of reservoir - mantle cavity - the “combustion chamber” of a living rocket, into which water is periodically sucked in. The mantle cavity contains gills and internal organs squid ( rice. 1b).

With a jet swimming method the animal sucks water through a wide open mantle gap into the mantle cavity from the boundary layer. The mantle gap is tightly “fastened” with special “cufflinks-buttons” after the “combustion chamber” of a living engine is filled with sea water. The mantle gap is located near the middle of the squid's body, where it is thickest. The force causing the movement of the animal is created by throwing a stream of water through a narrow funnel, which is located on the abdominal surface of the squid. This funnel, or siphon, is "nozzle" of a living jet engine.

The engine “nozzle” is equipped with a special valve and the muscles can turn it. By changing the angle of installation of the funnel-nozzle ( rice. 1c), the squid swims equally well, both forward and backward (if it swims backward, the funnel is extended along the body, and the valve is pressed against its wall and does not interfere with the water stream flowing from the mantle cavity; when the squid needs to move forward, the free end of the funnel elongates somewhat and bends in the vertical plane, its outlet collapses and the valve takes a curved position). Jet shocks and the absorption of water into the mantle cavity follow one after another with elusive speed, and the squid rushes like a rocket in the blue of the ocean.

Squid and its jet engine - Figure 1

1a) squid – live torpedo; 1b) squid jet engine; 1c) the position of the nozzle and its valve when the squid moves back and forth.

The animal spends a fraction of a second taking water in and pushing it out. By sucking water into the mantle cavity in the aft part of the body during periods of slow movements due to inertia, the squid thereby carries out suction of the boundary layer, thus preventing the flow from stalling during an unsteady flow regime. By increasing the portions of ejected water and increasing the contraction of the mantle, the squid easily increases its speed of movement.

The squid jet engine is very economical, thanks to which he can reach speed 70 km/h; some researchers believe that even 150 km/h!

Engineers have already created engine similar to a squid jet engine: This water cannon, operating using a conventional gasoline or diesel engine. Why squid jet engine still attracts the attention of engineers and is the object of careful research by biophysicists? To work underwater, it is convenient to have a device that works without access atmospheric air. The creative search of engineers is aimed at creating a design hydrojet engine, similar air-jet…

Based on materials from wonderful books:
“Biophysics in physics lessons” Cecilia Bunimovna Katz,
And "Primates of the Sea" Igor Ivanovich Akimushkina

Kondakov Nikolay Nikolaevich (1908–1999) – Soviet biologist, animal artist, Candidate of Biological Sciences. Main contribution to biological science the drawings he made became various representatives fauna. These illustrations were included in many publications, such as Great Soviet Encyclopedia, Red Book of the USSR, in animal atlases and teaching aids.

Akimushkin Igor Ivanovich (01.05.1929–01.01.1993) – Soviet biologist, writer and popularizer of biology, author of popular science books about animal life. Laureate of the All-Union Society "Knowledge" award. Member of the USSR Writers' Union. The most famous publication of Igor Akimushkin is a six-volume book "Animal World".

The materials in this article will be useful to apply not only in physics lessons And biology, but also in extracurricular activities.
Biophysical material is extremely beneficial for mobilizing the attention of students, for turning abstract formulations into something concrete and close, affecting not only the intellectual, but also the emotional sphere.

Literature:
§ Katz Ts.B. Biophysics in physics lessons

§ § Akimushkin I.I. Primates of the sea
Moscow: Mysl Publishing House, 1974
§ Tarasov L.V. Physics in nature
Moscow: Prosveshchenie Publishing House, 1988

Reactivity and movement through this is a fairly widespread phenomenon in nature. Well, scientists and inventors “spied” it and used it in their technical developments. Examples can be seen everywhere. Often we ourselves do not pay attention to the fact that this or that object - a living being, a technical mechanism - moves with the help of this phenomenon.

What is jet propulsion?

In living nature, reactivity is a movement that can occur in the event of separation of any particle from the body at a certain speed. In technology, the same principle is used - the law of conservation of impulses. Examples of jet propulsion of technology: in a rocket consisting of a shell (which also includes an engine, control devices, a useful area for moving cargo) and fuel with an oxidizer, the fuel burns, turning into gases that burst out through the nozzles in a powerful jet, giving the entire structure speed in the opposite direction.

Examples of jet propulsion in nature

Quite a few living creatures use this principle of movement. It is characteristic of the larvae of some species of dragonflies, jellyfish, and mollusks - scallop, cuttlefish, octopus, squid. And in flora- the flora of the Earth - there are also species that use this phenomenon for insemination.

"Squirting cucumber"

Flora provides us with examples of jet propulsion. Only by appearance This plant with a strange nickname is similar to the cucumbers we are used to. And it acquired the epithet “mad” because of the unusual way of spreading its seeds. When ripe, the fruits of the plant bounce off the stalks. This creates a hole through which the cucumber shoots a liquid containing seeds suitable for propagation using reactivity. And the fruit itself can fly up to 12 meters in the direction opposite to the shot.

How does a cuttlefish move?

Examples of jet propulsion are quite widely represented in the fauna. The cuttlefish is a cephalopod with a special funnel located in the front part of the body. Through it (and through an additional side slit) water enters the animal’s body, into the gill cavity. Then the liquid is sharply thrown out through a funnel, and the cuttlefish can direct a special tube to the side or back. The resulting reverse force provides movement in different directions.

Salpa

These animals are from the tunicate family - vivid examples jet propulsion in nature. They have translucent cylindrical bodies of small size and live in the surface waters of the world's oceans. When moving, the animal draws in water through a hole located in the front of the body. The liquid is placed in a wide cavity of its body, in which the gills are located diagonally. The salpa takes a sip of water, and at the same time the hole closes tightly, and the muscles of the body - transverse and longitudinal - contract. As a result, the entire body of the salpa contracts, and the water is sharply pushed out of the rear hole. Thus, salps use the principle of reactivity in their movement in the water element.

Jellyfish, mollusks, plankton

There are still inhabitants in the sea that move in a similar way. Everyone has probably met someone in the water at least once while relaxing on the coast. various types jellyfish But they also move using reactivity. Sea plankton, more precisely, some of it and scallops - they all move like this.

Examples of jet motion of bodies. Squid

The squid has a unique body structure. In fact, its structure contains a powerful jet engine with excellent efficiency. This representative of the fauna of the seas and oceans sometimes lives at great depths and reaches enormous sizes. Even the animal’s body resembles a rocket in its shape. More precisely, this modern rocket invented by scientists imitates the forms of squid created by nature. Moreover, for leisurely movements in the aquatic environment, a fin is used, but if a jerk is needed, then the principle of reactivity!

If you are asked to give examples of jet propulsion in nature, then first of all we can talk about this mollusk. Its muscular mantle surrounds a cavity located in the body. Water is sucked in from the outside and then thrown out quite sharply through a narrow nozzle (reminiscent of a rocket). Result: the squid moves jerkily in the opposite direction. This feature allows the animal to move with fairly high speeds, overtaking its prey or escaping from pursuit. It can reach speeds comparable to a well-equipped modern vessel: up to 70 kilometers per hour. And some scientists who study the phenomenon in detail talk about speeds reaching 150 km/h! In addition, this representative of the ocean has good maneuverability due to the tentacles, folded in a bunch, bending when moving in the right directions.