Municipal budgetary educational institution of the city of Ulyanovsk "Secondary school No. 75"
Creative work
"Archimedes' Law.
Floating bodies"
Completed by: 7B grade student
Simendeeva Diana
Head: physics teacher
Zakharova Galina Mikhailovna
Ulyanovsk
2017
Content
1Introduction: page 2
1.1 Goals and hypotheses. p.
32. Main content. p.4
2.1. Biography of Archimedes. pp.4,5
2.2
Archimedes' Law p.52.3. Conditions for floating bodies.
p.52.4 p.5
3. The order of work. p.6
3.1.Part I
3.2.Part II
4. Conclusions
5. Applications
6. Literature
1.1 Goals and hypotheses.
Goals:
Study the biography of Archimedes
Find out the floating conditions of bodies
Explore how it dependsF Aon the density and volume of the liquid
Hypotheses:
Does it depend F A from ρ and And v T
Sailing conditions depend onρ and And mg
2. Main part
2.1.Biography of Archimedes.
Archimedes (Fig. 1) was born in 287 BC in the city of Syracuse, located on the island of Sicily. Archimedes' father, Phidias, was a mathematician and astronomer. To receive his education, Archimedes went to the spiritual and scientific center of that era - Alexandria of Egypt.
In Alexandria, Archimedes received the basics of scientific knowledge and met the outstanding scientists of his time, the astronomer Conon of Samos and Eratosthenes of Cyrene. Archimedes maintained friendly correspondence with them until the end of his life. It must be assumed that it was in Alexandria, diligently visiting its famous library, that Archimedes became acquainted with the works of famous philosophers and geometers of the past - Eudoxus, Democritus and many others.
After completing his studies in Alexandria of Egypt, Archimedes returned to Syracuse. Already during his lifetime, legends were formed about Archimedes.
One of the most famous plots of the legends about Archimedes can be called “The Crown of King Hiero.” According to this legend, Archimedes was tasked with determining whether this crown was made of pure gold, or whether silver had been added to the gold during its manufacture. The solution to this problem came to Archimedes while he was taking a bath: by immersing the crown in water, you can find out its specific gravity by the displaced volume of liquid; it will be different for a golden crown and a crown “with an admixture”. With a cry of “Eureka!” Archimedes jumped out of the bath and ran naked through the streets of Syracuse. The solution to the problem with the crown laid the foundation for the science of hydrostatics, the founder of which was Archimedes, who outlined its foundations in his work “On the Floating of Bodies.” The force that pushes any body out of water is still called Archimedean force today.
Another legend tells that Archimedes managed to move the heavy multi-deck ship Syracuse with one movement of his hand thanks to the system of blocks he developed, the so-called pulley block.
“Give me a point of support, and I will change the world,” according to legend, Archimedes said in connection with this event. Using the lever to zoom
force is now used in all mechanical systems. Archimedes' inventions include the Archimedes screw, or auger, designed for scooping out water; it is still used in Egypt today.
The main science to which Archimedes devoted himself was mathematics. Archimedes' works show that he was extremely familiar with the mathematics and astronomy of his time. A number of Archimedes' works in the field of mathematics take the form of letters to his friends and colleagues. He carried out research in all areas of mathematics of his time: arithmetic, algebra, geometry.
The main problems of Archimedes' mathematical works are problems of finding surface areas and volumes, which can now be classified as mathematical analysis. As a result of his research, Archimedes found a general formula for calculating areas and volumes, based on the exhaustion method of his predecessor, the mathematician Eudoxus of Cnidus. Before Archimedes, no scientist could find an algorithm for calculating the surface area and volume of a sphere. This study, presented in the work “On the Sphere and the Cylinder,” was considered by Archimedes himself to be the pinnacle of his scientific research. According to legend, he asked to carve an image of a ball and a cylinder on his tombstone.
Archimedes' achievements in the field of astronomy include the construction of a “planetarium” to observe the movement of the five planets of the solar system, the rising of the Sun and the Moon. Archimedes tried to calculate the distances to the planets; his mistake was the geocentric worldview that was widespread at that time. In honor of Archimedes, remembering his astronomical research, a crater and a mountain range on the Moon, as well as one of the asteroids, were named. In Archimedes' hometown, Syracuse, one of the squares bears his name.
2.2 Archimedes' Law
Archimedes' law is formulated as follows:
a body immersed in a liquid (or gas) is subject to a buoyancy force equal to the weight of the liquid (or gas) in the volume of the immersed part of the body .
F A=pg V
(\displaystyle (F)_(A)=\rho (g)V,) Where R (\displaystyle\rho) - density of liquid (gas),(\displaystyle (g)) g is the acceleration of free fall, and(\displaystyle V) V - the volume of the submerged part of the body (or the part of the volume of the body located below the surface). If a body floats on the surface (moves uniformly up or down), then the buoyant force is equal in magnitude (and opposite in direction) to the force of gravity acting on the volume of liquid (gas) displaced by the body, and is applied to the center of gravity of this volume.
2.3. Conditions for floating bodies.
A solid body immersed in a liquid is acted upon by an Archimedean force F A and gravity mg. Depending on the ratio of forces mg and F A the body can sink, float and float to the surface. If mg > F A , the body drowns; if mg = F A , then the body floats inside the liquid or on its surface; if mg< F A , then the body floats up until the Archimedean force and the force of gravity are equal in magnitude. The body floats on the surface ifR f = R T ; the body drowns ifR t > R and ; the body floats up ifR T< R and.
2.4 .What does the buoyant force depend on?
Buoyancy force depends: from Vt, from liquid density, immersion depth, from shapeobject with equal volume.
3. The order of work.
3.1. Experiment with an egg.
Goal of the work :
Investigate the behavior of a raw egg in various types of liquids.
Prove the dependence of the buoyant force on the density of the liquid. Progress :
1.Take a raw egg and different types of liquids:
pure water,
saturated, saline solution,
2. Determine the force of gravity acting on an egg in air and in liquids of various kinds alternately.
Research results:
The resulting force acting on the eggs in air turned out to be greater than in liquid.
The resulting force acting on eggs in different types of liquids turned out to be different
Conclusion
3.2. Experiment with potatoes.
Goal of the work :
Investigate the behavior of potatoes in various types of liquids.
Prove the dependence of the buoyant force on the density of the liquid.
Progress :
1.Take potatoes and different types of liquids.
pure water,
saturated, saline solution,
2. Determine the force of gravity acting in liquids of various kinds.
Research results:
The resulting force acting on the potatoes in air was greater than in liquid.
The resulting force acting on potatoes in different types of liquids turned out to be different
(the greater the density of the liquid, the less the resulting force)
Conclusion
The experiment shows that the buoyancy force depends on the volume of the body and the density of the liquid. The resulting force, which determines the behavior of a body in a liquid, depends on the mass, volume of the body and the density of the liquid.
5. References
1.Internet resources
2. Physics 7th grade A.V. Peryshkin, DROFA Publishing House
6. Applications
(Fig.1)
When preparing a salt solution of a certain density, housewives immerse a raw egg in it: if the density of the solution is insufficient, the egg sinks, if it is sufficient, it floats. The density of sugar syrup during canning is determined in the same way. from the material in this paragraph you will learn when a body floats in a liquid or gas, when it floats and when it sinks.
We substantiate the floating conditions of bodies
You can probably give many examples of bodies floating. Ships and boats, wooden toys and balloons float, fish, dolphins and other creatures swim. What determines the body's ability to swim?
Let's conduct an experiment. Let's take a small vessel with water and several balls made of different materials. We will alternately immerse the bodies in water, and then release them without an initial speed. Further, depending on the density of the body, different options are possible (see table).
Option 1. Dive. The body begins to sink and eventually sinks to the bottom of the vessel. Let's find out why this happens. Two forces act on the body:
The body sinks, which means that the downward force is greater:
a body sinks in a liquid or gas if the density of the body is greater than the density of the liquid or gas.
Option 2. Floating inside the liquid. The body does not sink or float, but remains floating inside the liquid.
Try to prove that in this case the density of the body is equal to the density of the liquid:
a body floats inside a liquid or gas if the density of the body is equal to the density of the liquid or gas.
Option 3. Ascent. The body begins to float and eventually stops on the surface of the liquid, partially immersed in the liquid.
While the body floats up, the Archimedean force is greater than the force of gravity:
Stopping a body on the surface of a liquid means that the Archimedean force and the force of gravity are balanced: ^ strand = F arch.
a body floats in a liquid or gas or floats on the surface of a liquid if the density of the body is less than the density of the liquid or gas.
We observe the floating of bodies in wildlife
The bodies of the inhabitants of seas and rivers contain a lot of water, so their average density is close to the density of water. To move freely in a liquid, they must “control” the average density of their body. Let's give examples.
In fish with a swim bladder, such control occurs due to changes in the volume of the bladder (Fig. 28.1).
The nautilus mollusk (Fig. 28.2), which lives in tropical seas, can quickly float up and sink to the bottom again due to the fact that it can change the volume of internal cavities in the body (the mollusk lives in a spiral-twisted shell).
The water spider, widespread in Europe (Fig. 28.3), carries with it into the depths an air shell on its abdomen - it is this that gives it a reserve of buoyancy and helps it return to the surface.
Learning to solve problems
Task. A copper ball weighing 445 g has a cavity inside with a volume of 450 cm 3. Will this ball float in water?
Analysis of a physical problem. To answer the question of how a ball will behave in water, you need to compare the density of the ball (sphere) with the density
in °dy (water).
To calculate the density of a ball, you need to determine its volume and mass. The mass of air in the ball is insignificant compared to the mass of copper, so t of the ball = t of copper. The volume of the ball is the volume of the copper shell. Copper and the volume of the cavity V - . The volume of the copper shell can be determined by knowing
mass and density of copper.
We learn about the densities of copper and water from density tables (p. 249).
It is advisable to solve the problem in the presented units.
2. Knowing the volume and mass of the ball, we determine its density:
Analysis of the result: the density of the ball is less than the density of water, so the ball will float on the surface of the water.
Answer: yes, the ball will float on the surface of the water.
Let's sum it up
A body sinks in a liquid or gas if the density of the body is greater than the density of the liquid or gas (p t >p g) · A body floats inside a liquid or gas if the density of the body is equal to the density of the liquid or gas (t = p g). A body floats in a liquid or gas or floats on the surface of a liquid if the density of the body is less than the density of the liquid or gas
Control questions
1. Under what condition will a body sink in a liquid or gas? Give examples. 2. What condition must be met for a body to float inside a liquid or gas? Give examples. 3. Formulate the condition under which a body in a liquid or gas floats up. Give examples. 4. Under what condition will a body float on the surface of a liquid? 5. Why and how do the inhabitants of seas and rivers change their density?
Exercise No. 28
1. Will a uniform lead block float in mercury? in water? in sunflower oil?
2. Place the balls shown in Fig. 1, in order of increasing density.
3. Will a block with a mass of 120 g and a volume of 150 cm 3 float in water?
4. According to Fig. 2 Explain how a submarine dives and surfaces.
5. The body floats in kerosene, completely immersed in it. Determine the mass of the body if its volume is 250 cm3.
6. Three liquids that do not mix were poured into the vessel - mercury, water, kerosene (Fig. 3). Then three balls were lowered into the vessel: steel, foam and oak.
How are the layers of liquids arranged in the vessel? Determine which ball is which. Explain your answers.
7. Determine the volume of the part of the amphibious vehicle submerged in water if an Archimedean force of 140 kN acts on the vehicle. What is the mass of the amphibious vehicle?
8. Compose a problem inverse to the problem discussed in § 28 and solve it.
9. Establish a correspondence between the density of a body floating in water and the part of this body located above the surface of the water.
Ar t = 400 kg/m 3 1 0
B r t = 600 kg/m 3 2 °D
Vrt = 900 kg/m 3 3 0, 4
G r t = 1000 kg/m 3 4 0, 6
10. A device for measuring the density of liquids is called a hydrometer. Using additional sources of information, learn about the structure of a hydrometer and the principle of its operation. Write instructions on how to use a hydrometer.
11. Fill out the table. Consider that in each case the body is completely immersed in the liquid.
Experimental task
"Cartesian Diver". Make a physical toy inspired by the French scientist Rene Descartes. Pour water into a plastic jar with a tight-fitting lid and place a small beaker (or small medicine bottle) partially filled with water, hole down, in it (see picture). There should be enough water in the beaker so that the beaker protrudes slightly above the surface of the water in the jar. Close the jar tightly and squeeze the sides together. Observe the behavior of the beaker. Explain the operation of this device.
LABORATORY WORK No. 10
Subject. Determination of the floating conditions of bodies.
Purpose: to experimentally determine under what conditions: a body floats on the surface of a liquid; the body floats inside the liquid; the body sinks in the liquid.
Equipment: test tube (or small medicine bottle) with a stopper; thread (or wire) 20-25 cm long; container with dry sand; a measuring cylinder half filled with water; scales with weights; paper napkins.
instructions for work
Preparing for the experiment
1. Before you begin, make sure you know the answers to the following questions.
1) What forces act on a body immersed in a liquid?
2) What formula is used to find the force of gravity?
3) What formula is used to find the Archimedean force?
4) What formula is used to find the average density of a body?
2. Determine the scale division value of the measuring cylinder.
3. Secure the test tube to the thread so that, holding the thread, you can immerse the test tube into the measuring cylinder and then remove it.
4. Remember the rules for working with scales and prepare the scales for use. Experiment
Strictly follow the safety instructions (see flyleaf). Immediately enter the measurement results into the table.
Experiment 1. Determination of the condition under which a body sinks in a liquid.
1) Measure the volume of water V 1 in the measuring cylinder.
2) Fill the test tube with sand. Close the plug.
3) Lower the test tube into the measuring cylinder. As a result, the test tube should be at the bottom of the cylinder.
4) Measure the volume V 2 of water and test tubes; determine the volume of the test tube:
5) Take out the test tube and wipe it with a napkin.
6) Place the test tube on the scales and measure its mass to the nearest 0.5 g. Experiment 2. Determining the condition under which a body floats inside a liquid.
1) By pouring sand out of the test tube, make sure that the test tube floats freely inside the liquid.
Experiment 3. Determination of the condition under which a body rises and floats on the surface of a liquid.
1) Pour some more sand out of the test tube. Make sure that after being completely immersed in the liquid, the test tube floats to the surface of the liquid.
2) Repeat the steps described in points 5-6 of experiment 1.
Processing the experiment results
1. For each experience:
1) make a schematic drawing in which you depict the forces acting on the test tube;
2) calculate the average density of the test tube with sand.
2. Enter the calculation results into the table; complete filling it out.
Analysis of the experiment and its results
After analyzing the results, draw a conclusion indicating under what condition: 1) the body sinks in the liquid; 2) the body floats inside the liquid; 3) the body floats on the surface of the liquid.
Creative task
Suggest two ways to determine the average density of an egg. Write down a plan for each experiment.
This is textbook material
Floating is the ability of the body to stay on the surface of a liquid or at a certain level inside a liquid.
We know that any body in a liquid is acted upon by two forces directed in opposite directions: gravity and Archimedean force.
The force of gravity is equal to the weight of the body and is directed downward, while the Archimedean force depends on the density of the liquid and is directed upward. How does physics explain the floating of bodies, and what are the conditions for floating bodies on the surface and in the water column?
Archimedean force is expressed by the formula:
Fout = g*m f = g* ρ f * V f = P f,
where m is the mass of the liquid,
and Pf is the weight of the fluid displaced by the body.
And since our mass is equal to: m f = ρ f * V f, then from the formula of the Archimedean force we see that it does not depend on the density of the immersed body, but only on the volume and density of the fluid displaced by the body.
Archimedean force is a vector quantity. The reason for the existence of the buoyant force is the difference in pressure on the upper and lower parts of the body. The pressure indicated in the figure is P 2 > P 1 due to the greater depth. For the Archimedes force to arise, it is enough that the body is at least partially immersed in the liquid.
So, if a body floats on the surface of a liquid, then the buoyant force acting on the part of this body immersed in the liquid is equal to the gravitational force of the entire body. (Fa = P)
If the force of gravity is less than the Archimedean force (Fa > P), then the body will rise from the liquid, that is, float.
In the case when the weight of the body is greater than the Archimedean force pushing it out (Fa
From the obtained ratio, important conclusions can be drawn:
The buoyancy force depends on the density of the liquid. Whether a body sinks or floats in a liquid depends on the density of the body.
A body floats when completely immersed in a liquid if the density of the body is equal to the density of the liquid
A body floats, partially protruding above the surface of the liquid, if the density of the body is less than the density of the liquid
- if the density of the body is greater than the density of the liquid, swimming is impossible.
Fishermen's boats are made of dry wood, the density of which is less than that of water.
Why do ships float?
The hull of a ship that is immersed in water is made voluminous, and inside this ship has large cavities filled with air, which greatly reduce the overall density of the ship. The volume of water displaced by the ship is thus greatly increased, increasing its buoyancy force, and the total density of the ship is made less than the density of water, so that the ship can float on the surface. Therefore, each ship has a certain limit on the mass of cargo that it can carry. This is called the ship's displacement.
Sailing conditions
Purpose of the lesson: to clarify the conditions for the floating of bodies depending on the density of matter and liquid.
Educational:
familiarization of students with concepts: the condition of floating bodies
formation of a holistic perception of the scientific picture of the world
Educational:
development of students' operational thinking style;
development of students’ synthetic thinking;
development of skill and skill in conducting experiments;
continuation of work on the development of intellectual skills: highlighting the main thing, analysis, ability to draw conclusions, specification;
Educators:
developing students' interest in studying physics;
nurturing accuracy, ability and skill in rational use of one’s time, planning one’s activities.
Equipment for the lesson:
Test tube with stopper, potato ball, plasticine, water, saturated salt solution, vessel, dynamometer, scales with weights
1. Introduction. Updating knowledge.
Today a student in your class will start the lesson. So let's listen carefully
The blue whale's tongue weighs 3 tons, its liver weighs 1 ton, its heart weighs 600-700 kg, its blood weighs 10 tons, the diameter of its dorsal artery is 40 cm, and its stomach contains 1-2 tons of food; whale's mouth - room with an area of 24 m2. IN thrown ashore, dies almost instantly.
An interesting plant lives in the Pacific Ocean - this is macrocystis. Its length reaches 57 meters and its weight is 100 kilograms. This algae is called bladderwrack. Near each leaf blade there is a bubble the size of a large apple. The shell is thick, you won’t puncture it! It is inflated tightly, tightly with some kind of gas that the algae itself produces. This plant is very useful.
L hogs and ducks, heavy and clumsy on the shore, But so light and graceful in the water.
G a ship made of iron sinks, but a ship made of iron floats
2. Formulate the topic of the lesson???
Sailing conditions
Lesson objectives:
Learn to derive formulas for the floating conditions of bodies.
Learn to work with instruments, observe, analyze and compare experimental results, and draw conclusions.
Find out the condition under which a body sinks in a liquid, and the condition for the floating of bodies completely immersed in a liquid.
3.Experience:
– I have in my hands several blocks and balls of the same volume. Will the buoyancy forces of these bodies be the same when they are immersed in water? (same)
- Let's try to put them in the water. What do we see? Some bodies drowned, others floated. Why? What else did we not take into account when we talked about immersing bodies in liquid?
Conclusion from experience:
This means whether a body sinks or not depends not only on the force of Archimedes, but also on the force of gravity.
4. Let's repeat the material from the previous lesson
What force is called Archimedean force?
On what quantities does it depend?
What formula is used to calculate it?
How else can you determine buoyancy force?
In what units is it measured?
How is the Archimedean force directed?
How to determine gravity
What is the direction of gravity?
What is the resultant force?
How is the resultant of two forces directed along one straight line in one direction found? In different directions?
How will a body behave under the influence of two equal but oppositely directed forces?
5. Presentation of new material. Primary consolidation.
Let's look at different situations
(Ft >FA) (Ft =FA) (Ft< FА)
Let's make assumptions (hypothesis)
if the force of gravity is greater than the force of Archimedes (Ft > FA) -- The body sinks
if the force of gravity is equal to the force of Archimedes (Ft = FA) – The body floats,
if the force of gravity is less than the force of Archimedes (Ft< FА) ---Тело всплывает
The assumption must be tested experimentally.
Before you are various bodies and devices.
What materials should be used to prove our assumptions?
(dynamometer, liquid, body)
What measurements to make (determine the Archimedes force and the force of gravity and compare them with each other) or calculate using formulas.
Fill out the table
A= ρ andV g =F t = mg =
conclusion (the ratio of gravity and Archimedean force determines the ability of the body: to swim, sink or float)
The ratio of gravity and Archimedean force determines the body’s ability to swim, sink or float.
Demonstrations: 1. A test tube body floats in water. 2. A potato ball sinks in water. 3. The same potato ball floats in salt water. 4. A plasticine ball sinks in water 5. A plasticine boat floats in water
In order for a body to float, it is necessary that the force of gravity acting on it be balanced by the Archimedean (buoyant) force.
F t = F a (1)
Archimedean force: F a = ρ f V f g (2)
Gravity: F t = mg = ρVg (3)
Let's substitute expressions (2) and (3) into equality (1): ρVg = ρ f V f g
Dividing both sides of this equality by g, we obtain the condition for the floating of bodies in a new form:
ρV = ρ f V f
For a body to float, partially protruding above the surface of the liquid, the density of the body must be less than the density of the liquid. When the density of the body is greater than the density of the liquid, the body sinks, because the force of gravity exceeds the Archimedean force.
Analysis of the exercise:
– What substances (ice, stearin, wax, rubber, brick) will float in water, milk, mercury?
– Using the table, determine which metals sink in mercury? (osmium, iridium, platinum, gold)
– What substances will float in kerosene? (cork, pine, oak)
4. Application of floating conditions for bodies
A) Sailing ships
- And now we must explain why a steel nail sinks, but a ship made of steel floats?
- Let's take plasticine. If you put it in water, it drowns. How to make sure he doesn't drown?
B) Swimming of fish and whales
How can fish and whales change their diving depth? (fish due to a change in the volume of the swim bladder, whales due to a change in the volume of the lungs, which means due to the force of Archimedes)
The density of living organisms inhabiting the aquatic environment differs very little from the density of water, so their weight is almost completely balanced by the Archimedean force. A fish can change the volume of its body by compressing its swim bladder with the efforts of its pectoral and abdominal muscles, thereby changing the average density of its body, thanks to which it can regulate the depth of its dive.
The swim bladder of a fish easily changes its volume. When a fish, with the help of muscles, descends to a greater depth and the water pressure on it increases, the bubble contracts, the volume of the fish’s body decreases and it swims in the depths. When rising, the swim bladder and volume of the fish increases and it floats to the surface. This is how the fish regulates the depth of its dive. Swim bladder of a fish This is interesting
Whales regulate their dive depth by increasing and decreasing their lung capacity. This is interesting
The average density of living organisms inhabiting the aquatic environment differs little from the density of water, so their weight is almost completely balanced by the Archimedean force. Thanks to this, aquatic animals do not need strong and massive skeletons. For the same reason, the trunks of aquatic plants are elastic.
Birds have a thick, water-impervious layer of feathers and down, which contains a significant amount of air, due to which the average density of their body is very low, so ducks do not submerge much in the water when swimming.
B) Submarine navigation
– How can submarines rise and fall to different depths? (due to changes in its mass, and therefore gravity)
D) Human swimming in fresh water and salt water
The average density of the human body is 1030 kg/m. Will a person swim or drown in the river and in the salt lake?
Floating bodies
203. A swimmer lying motionless on his back on the water takes a deep breath and exhales. How does the position of the swimmer’s body change in relation to the surface of the water? Why?
204. Are the buoyancy forces acting on the same wooden block floating first in water and then in kerosene the same?
205. Why does a plate placed flat on the surface of the water float, but one placed edge-on into the water sinks?
206. Can a lifebuoy hold any number of people who grab onto it?
207. Heavy lead plates are placed on the chest and back of the diver, and lead soles are attached to the shoes. Why do they do this?
208. A piece of wood is lowered into a vessel with water. Will this change the pressure at the bottom of the vessel if water does not pour out of the vessel?
209. A glass is filled to the brim with water. A piece of wood is placed in it so that it floats freely. Will the weight of the glass change if water still fills it to the brim?
Answers:203. When inhaling, the swimmer floats up, and when exhaling, he plunges deeper into the water, since when breathing, the volume of the chest changes and the Archimedean force changes accordingly.
(When inhaling, the swimmer floats up, when exhaling, he plunges deeper into the water, since during breathing the volume of the chest changes, but the body weight remains almost constant. Therefore, the total volume of the body increases when inhaling, decreases when exhaling, and the volume of the part of the body immersed in water does not change.)
204. Same. The block floats in both fluids, which means that the buoyant force in each of them is equal to the force of gravity acting on it.
206. No, since the lifting force (the difference between the maximum Archimedean force and the force of gravity) of a circle has a limited value.
207. To increase the force of gravity and make it greater than the Archimedean force, otherwise the diver will not dive to the required depth.
208. The pressure will increase as the water level in the vessel rises.
209. It will not change, since the weight of a piece of wood is equal to the weight of the water displaced by it (and poured out of the glass).
6. Experimental task.
Determine body weight:m=
DefineFt according to the formula and using a dynamometer, fill out the table.
Define FAUsing the formula and using a dynamometer, fill out the table.
Formulate a conclusion (the ratio of gravity and Archimedean force determines the ability of the body: to swim, sink or float)
Fill out the table
A= ρ andV g =F t = mg =
conclusion(based on experiment)
conclusion (in fact)
F t =
7. Homework:
8.Conclusion: with Now our lesson time is coming to an end. And although we have not solved all the problems, our journey along the roads of physics does not end!