The buoyant force of Archimedes cartoon. Archimedes' law: the history of discovery and the essence of the phenomenon for dummies
EXPERIENCES on the topic "Archimedean force"
Science is wonderful, interesting and fun. But it’s hard to believe in miracles from words, you have to touch them with your own hands. There is an experience - entertaining!
And if you are careful
Mind independent
And with physics on "you"
That experience is entertaining -
Cheerful, exciting -
Will reveal secrets to you
And new dreams!
1) Living and dead water
Put on the table a liter glass jar filled 2/3 with water, and two glasses with liquids: one with the inscription "living water", the other with the inscription "dead". Dip a potato tuber (or a raw egg) into a jar. He is drowning. Add “live” water to the jar - the tuber will float, add “dead” water - it will sink again. By adding one or another liquid, you can get a solution in which the tuber will not float to the surface, but will not go to the bottom either.
The secret of the experiment is that in the first glass there is a saturated solution of table salt, in the second - ordinary water. (Tip: before demonstration, it is better to peel the potatoes, and pour a weak solution of salt into the jar so that even a slight increase in its concentration causes an effect).
2) Carthusian pipette diver
Fill the pipette with water so that it floats vertically, almost completely submerged in water. Dip the diver's pipette into a clear plastic bottle filled to the brim with water. Close the bottle tightly with a cap. When pressing on the walls of the vessel, the diver will begin to fill with water. By changing the pressure, get the diver to follow your commands: “Down!”, “Up!” and "Stop!" (stop at any depth).
3) Unpredictable potatoes
(Experiment can be done with an egg). Dip the potato tuber in a glass vessel half filled with an aqueous solution of table salt. He floats on the surface.
What happens to potatoes if you add water to a vessel? The usual answer is that the potatoes will float. Pour water carefully (its density is less than the density of the solution and eggs) through the funnel along the wall of the vessel until it is full. Potatoes, to the surprise of the audience, remain at the same level.
4) Spinning peach
Pour into a glass of sparkling water. The carbon dioxide dissolved in the liquid under pressure will begin to come out of it. Place a peach in a glass. It will immediately float to the surface and ... begin to rotate like a wheel. It will behave like this for quite a long time.
In order to understand the reason for this rotation, take a closer look at what is happening. Pay attention to the velvety skin of the fruit, to the hairs of which gas bubbles will stick. Since there will always be more bubbles on one half of the peach, a large buoyant force acts on it, and it turns up.
5) The force of Archimedes in bulk matter
At the Archimedes Legacy performance, the inhabitants of Syracuse competed in "getting a pearl from the bottom of the sea." A similar but simpler demonstration can be repeated using a small glass jar of millet (rice). Place a tennis ball (or cork stopper) in it and close the lid. Turn the jar over so that the ball is in its lower part under the millet. If you create a slight vibration (lightly shake the jar up and down), then the friction force between the grains of millet will decrease, they will become mobile, and after a while the ball will float to the surface under the action of the force of Archimedes.
6) The package flew without wings
Place a candle, light it, hold a bag over it, the air in the bag will heat up,
After releasing the package, see how the package will fly up under the action of the Archimedes force.
7) Different swimmers swim differently
Pour water and oil into a vessel. Lower the nut, plug and pieces of ice. The nut will be at the bottom, the plug will be on the surface of the oil, the ice will be on the surface of the water under a layer of oil.
This is due to the conditions of swimming bodies:
the force of Archimedes is greater than the gravity of the cork - the cork floats on the surface,
the force of Archimedes is less than the force of gravity acting on the nut - the nut sinks
the Archimedes force acting on a piece of ice is greater than the gravity of the ice - the cork floats on the surface of the water, but since the density of the oil is less than the density of water, and less than the density of ice - the oil will remain on the surface above the ice and water
8) Experience confirming the law
Hang the bucket and cylinder from the spring. The volume of the cylinder is equal to the internal volume of the bucket. Spring extension is marked with a pointer. Immerse the entire cylinder in a pouring vessel filled with water. Water is poured into a glass.
The volume of spilled water isaboutvolume of a body submerged in water. The spring pointer marks the reduction in the weight of the cylinder in the water caused by the actioninbuoyant force.
Pour water from the glass into the bucket and you will see that the spring pointer returns to its initial position. So, under the action of the Archimedean force, the spring contracted, and under the influence of the weight of the displaced water, it returned to its original position. The Archimedean force is equal to the weight of the fluid displaced by the body.
9) Lost balance
Make a paper cylinder, hang upside down on a lever and balance.
Let's bring the spirit lamp under the cylinder. Under the action of heat, the balance is disturbed, the vessel rises. As the power of Archimedes grows.
Suchshells filled with warm gas or hot air are called balloons and are used for aeronautics.
CONCLUSION
After doing experiments, we were convinced that bodies immersed in liquids, gases and even bulk substances are affected by the force of Archimedes, directed vertically upwards. The Archimedean force does not depend on the shape of the body, the depth of its immersion, the density of the body and its mass. The Archimedes force is equal to the weight of the liquid in the volume of the submerged part of the body.
It would seem that there is nothing simpler than the law of Archimedes. But once Archimedes himself broke his head over his discovery. How it was?
An interesting story is connected with the discovery of the basic law of hydrostatics.
Interesting facts and legends from the life and death of Archimedes
In addition to such a gigantic breakthrough as the discovery of the actual law of Archimedes, the scientist also has a whole list of merits and achievements. In general, he was a genius who worked in the fields of mechanics, astronomy, and mathematics. He wrote such works as a treatise "on floating bodies", "on a ball and a cylinder", "on spirals", "on conoids and spheroids" and even "on grains of sand". In the latest work, an attempt was made to measure the number of grains of sand needed to fill the universe.
The role of Archimedes in the siege of Syracuse
In 212 BC, Syracuse was besieged by the Romans. The 75-year-old Archimedes designed powerful catapults and short-range light throwing machines, as well as the so-called "Archimedes' claws". With their help, it was possible to literally turn over enemy ships. Faced with such powerful and technological resistance, the Romans could not take the city by storm and were forced to begin a siege. According to another legend, Archimedes, with the help of mirrors, managed to set fire to the Roman fleet by focusing the sun's rays on the ships. The veracity of this legend seems doubtful, because. none of the historians of that time mentions this.
Death of Archimedes
According to many testimonies, Archimedes was killed by the Romans when they did take Syracuse. Here is one of possible versions death of a great engineer.
On the porch of his house, the scientist pondered the diagrams that he drew with his hand right on the sand. A passing soldier stepped on the drawing, and Archimedes, immersed in thought, shouted: "Get away from my drawings." In response to this, a soldier hurrying somewhere simply pierced the old man with a sword.
Well, now about the sore point: about the law and the power of Archimedes ...
How was the law of Archimedes discovered and the origin of the famous "Eureka!"
Antiquity. Third century BC. Sicily, where there is still no mafia, but there are ancient Greeks.
Inventor, engineer and theoretical scientist from Syracuse (Greek colony in Sicily) Archimedes served under King Hieron II. Once jewelers made a golden crown for the king. The king, as a suspicious person, called the scientist to him and instructed him to find out if the crown contained silver impurities. It must be said here that at that distant time no one decided similar questions and the occasion was unprecedented.
Archimedes thought for a long time, did not come up with anything, and one day decided to go to the bathhouse. There, sitting in a bowl of water, the scientist found a solution to the problem. Archimedes drew attention to a completely obvious thing: the body, plunging into water, displaces a volume of water equal to its own volume of the body.
Just then, without even bothering to get dressed, Archimedes jumped out of the bath and shouted his famous "Eureka", which means "found." Appearing to the king, Archimedes asked to give him ingots of silver and gold, equal in weight to the crown. By measuring and comparing the volume of water displaced by the crown and the ingots, Archimedes discovered that the crown was not made of pure gold, but had silver impurities. This is the story of the discovery of the law of Archimedes.
The essence of the law of Archimedes
If you are asking yourself how to understand Archimedes' principle, we will answer. Just sit down, think, and understanding will come. In fact, this law says:
A body immersed in a gas or liquid is acted upon by a buoyant force equal to the weight of the liquid (gas) in the volume of the immersed part of the body. This force is called the Archimedes force.
As you can see, the Archimedes force acts not only on bodies immersed in water, but also on bodies in the atmosphere. The force that makes the balloon rise up is the same force of Archimedes. The Archimedean force is calculated using the formula:
Here the first term is the density of the liquid (gas), the second is the acceleration free fall, the third is the volume of the body. If the force of gravity is equal to the force of Archimedes, the body floats, if it is greater, it sinks, and if it is less, it floats until it starts to float.
In this article, we examined the law of Archimedes for dummies. If you want to know how to solve problems where there is Archimedes' law, please contact our specialists. Best Authors they will gladly share their knowledge and put the solution of the most difficult task “on the shelves”.
Release 8
In the video lesson of physics from the Academy entertaining sciences Professor Daniil Edisonovich will talk about the ancient Greek scientist Archimedes and some of his amazing discoveries. How do you know if gold is pure? How do multi-ton ships manage to float on ocean waves? Our life is full of mysterious phenomena and tricky puzzles. Physics can pick up clues to some of them. After watching the eighth video lesson of physics, you will get acquainted with the law of Archimedes and Archimedean force as well as the history of their discovery.
Law of Archimedes
Why do objects weigh less in water than on land? For a person, being in water is comparable to being in a state of weightlessness. It is used in their training astronauts. But why is this happening? The fact is that a buoyant force, discovered by the ancient Greek philosopher Archimedes, acts on bodies immersed in water. The law of Archimedes sounds like this - a body immersed in a liquid loses as much weight as the volume of water displaced by it weighs. The buoyant force was named Archimedean, in honor of the discoverer. Archimedes was one of the greatest scientists Ancient Greece. This brilliant mathematician and mechanic lived in Syracuse in the 3rd century BC. e. At this time, King Hieron ruled in Syracuse. Once Hieron, having received from the masters the golden crown ordered by him, doubted their honesty. It seemed to him that they concealed part of the gold issued for its manufacture, and replaced it with silver. But how to convict jewelers of a fake? Hiero instructed Archimedes to determine if there was an admixture of silver in the golden crown. Archimedes was constantly looking for a solution to the problem, never ceasing to think about it when he was busy with other things. And the solution was found ... in the bath. Archimedes soaped himself with ashes and climbed into the bath. And what happened every time when any person, not even a scientist, sits in any, not even a marble bath - the water in it rises. But what Archimedes usually did not pay any attention to, suddenly interested him. He got up - the water level dropped, he sat down again - the water rose; moreover, it rose as the body sank. And at that moment it dawned on Archimedes. He saw in a dozen experiments carried out a hint of how the volume of a body is related to its weight. And I realized that the task of King Hieron was solvable. And he was so delighted with his accidental discovery that, as he was - naked, with the remains of ashes on his body - he ran home through the city, filling the street with shouts: “Eureka! Eureka!". This is how Archimedes, according to the legend, found the solution to Hiero's problem. Archimedes asked the king for two ingots - silver and gold. The weight of each ingot was equal to the weight of the crown. Putting a silver and then a gold ingot into a vessel filled to the brim with water, the scientist measured the volume of water displaced by each of the ingots. Gold supplanted less water than silver. And all because the volume of a piece of gold was less than a piece of silver of the same weight. After all, gold is heavier than silver. Then Archimedes immersed the crown in the vessel and measured the volume of water displaced by it. The crown displaced less water than a piece of silver. but more than a bar of gold. So the jeweler's fraud was exposed. Thanks to the Archimedean force, giant ships weighing hundreds of thousands of tons are able to float. This is due to the fact that they have a large displacement. That is, their volume is such that it displaces great amount water. And as you remember, the larger the volume of the body, the stronger the Archimedean force acts on it.