Reactivity and movement with this is a fairly widespread occurrence in nature. Well, scientists and inventors “spied” and used it in their technical developments. Examples of jet propulsion can be seen everywhere. Often we ourselves do not pay attention to the fact that an object - a living being, a technical mechanism - moves with the help of this phenomenon.
What is jet propulsion?
In wildlife, reactivity is a movement that can occur if a particle is separated from the body at a certain speed. In technology, a jet engine uses the same principle - the law of conservation of momenta. Examples of jet propulsion technology: in a rocket consisting of a shell (which also includes an engine, control devices, useful area for moving goods) and fuel with an oxidizer, the fuel burns, turning into gases, which are blown out through nozzles with a powerful jet, giving the whole structure speed in the opposite direction.
Examples of jet propulsion in nature
Quite a few living things use this principle of movement. It is characteristic of the larvae of some species of dragonflies, jellyfish, mollusks - scallops, cuttlefish, octopuses, squids. And in the plant world - the flora of the Earth - there are also species that use this phenomenon for insemination.
"Squirting cucumber"
Examples of jet propulsion are provided by the flora. Only in appearance does this plant with a strange nickname resemble the usual cucumbers. And it acquired the epithet "rabid" because of the not quite familiar way of spreading its seeds. Ripening, the fruits of the plant bounce off the stalks. As a result, an opening is formed through which the cucumber shoots with a liquid containing seeds suitable for propagation using reactivity. And the fetus itself can fly off up to 12 meters in the direction opposite to the shot.
How is cuttlefish moving?
Examples of jet propulsion are quite widely represented in the fauna. Cuttlefish is a cephalopod mollusk having a special funnel located in front of the body. Through it (and even through an additional lateral gap), water enters the body of the animal, into the gill cavity. Then the liquid is sharply ejected through the funnel, and the cuttlefish can direct the special tube sideways or backward. The resulting reverse force provides movement in different directions.
Salpa
These animals from the family of shells are vivid examples of jet propulsion in nature. They have small translucent cylindrical bodies and live in the surface waters of the oceans. When moving, the animal draws water through the hole located in the front of the body. The fluid is placed in the wide cavity of his body, in which the gills are located diagonally. 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. From this, the whole body of the salpa is compressed, and the water is abruptly pushed away from the back opening. Thus, salps use the principle of reactivity in their movement in the water element.
Jellyfish, mollusks, plankton
In the sea there are still inhabitants who move in this way. All at least once for sure, resting on the coast, met in the water various types of jellyfish. But they also move using reactivity. Sea plankton, more precisely, some of its species, mollusks and scallops - they all move like that.
Examples of jet propulsion tel. Squid
Squid has a unique body structure. In essence, a powerful jet engine with excellent efficiency is laid in its structure by nature. This representative of the fauna of the seas and oceans sometimes lives at great depths and reaches enormous size. Even the body of an animal resembles a rocket in its forms. 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 you need a jerk, then the principle of reactivity!
If you are asked: give examples of jet propulsion in nature, then first of all we can talk about this mollusk. His muscular mantle surrounds the cavity located in the body. Water is sucked in from the outside, and then ejected quite sharply through a narrow nozzle (resembling a rocket). Result: the squid jerks in the opposite direction. This feature allows the animal to move at fairly high speeds, overtaking its prey or moving away from the chase. He can develop speed to match a well-equipped modern ship: up to 70 kilometers per hour. And some scientists who study the phenomenon in detail speak of speeds reaching 150 km / h! In addition, this representative of the ocean has good maneuverability due to tentacles folded in a beam, bending when moving in the right directions.