Sequential interaction between atoms or molecules of two substances with ...
Slide 1.
Solving tasks. Gravitational forces. 9-10 class.
Slide 2.
Does the strength of attraction to the sun act on a person? How to explain the occurrence of tides and tissions in the ocean? Explain the physical meaning of the gravitational constant?
Frontal survey of students:
Slide 3.
How many times will the force of attraction between bodies with an increase in the distance between them 5 times? A. will increase 5 times; B. decreases 5 times; C. decreases 25 times. 2. How many times will the force of attraction between the bodies with a decrease in the mass of each body 2 times? A. will increase by 2 times; B. decrease 4 times; C. will decrease by 4 times.
Task:
Slide 4.
3. How many times will the force of attraction between the bodies, with an increase in the distance between them 2 times and the increase in the mass of one of them 4 times? A. It will increase by 8 times B. Changes C. will decrease by 2 times how many times will change the force of attraction between bodies with a decrease in the mass of one of the bodies 2 times and increasing the distance between them 2 times? A. It will increase by 2 times B. It will decrease by 4 times C. It will decrease 8 times
Slide 5.
Solving the task:
1. On the astronaut on the surface of the Earth, the strength of 720 N. What is the strength of gravity on the same astronaut in a spacecraft located at a distance of two earth radii from the ground surface? A) 180 H b) 80 N c) 360 nd) 240
Slide 6.
2. Two bodies weighing 103 kg and 2 · 103 kg are apart from each other at a distance of R and attract with force F. What is the force of attraction of bodies weighing 2 · 103 kg and 4 · 103 kg, located at the same distance r? A) f b) 2f c) 4f g) 8f
Slide 7.
3. On the surface of the Earth on the astronaut in the Space, the strength of gravity is 1000 N. on the surface of the planet with a radius of 2 times less ground and weighing 2 times less mass of the Earth The strength of gravity acting on this astronaut will be equal to: a) 500 H b) 1000 N c) 2000 n d) 4000 n
Slide 8.
4. Which of the above statements are correct? A) The world's strength keeps the planet on their orbits around the sun b) The world's strength will change if you change the density of one of the attractive bodies B) with a free drop of a heavier body falls faster than the lighter, if they are reset from the same height d) if The body does not act on the body, the body is in a state of weightlessness.
1 Slide
Solving tasks. Gravitational forces. 9-10 class.
2 Slide
Does the strength of attraction to the sun act on a person? How to explain the occurrence of tides and tissions in the ocean? Explain the physical meaning of the gravitational constant? Frontal survey of students:
3 Slide
How many times will the force of attraction between bodies with an increase in the distance between them 5 times? A. will increase 5 times; B. decreases 5 times; C. decreases 25 times. 2. How many times will the force of attraction between the bodies with a decrease in the mass of each body 2 times? A. will increase by 2 times; B. decrease 4 times; C. will decrease by 4 times. Task:
4 Slide
3. How many times will the force of attraction between the bodies, with an increase in the distance between them 2 times and the increase in the mass of one of them 4 times? A. It will increase by 8 times B. Changes C. will decrease by 2 times how many times will change the force of attraction between bodies with a decrease in the mass of one of the bodies 2 times and increasing the distance between them 2 times? A. It will increase by 2 times B. It will decrease by 4 times C. It will decrease 8 times
5 Slide
Solving the task: 1. At the astronaut, which is on the surface of the Earth, the strength of 720 N. What is the strength of grave to act on the same astronaut in a spacecraft located at a distance of two terrestrial radii from the surface of the Earth? A) 180 H b) 80 N c) 360 nd) 240
6 Slide
Task: 2. Two bodies weighing 103 kg and 2 · 103 kg are from each other at a distance of R and are attracted with force F. What is the force of attraction of bodies weighing 2 · 103 kg and 4 · 103 kg, located at the same distance R ? A) f b) 2f c) 4f g) 8f
7 Slide
Task: 3. On the surface of the Earth on the astronaut in the scaffle, the strength of gravity 1000 N. on the surface of the planet with a radius is 2 times less than the earth and weighing 2 times less than the mass of the Earth, the strength of gravity acting on this astronaut will be equal to: a) 500 N B) 1000 N c) 2000 n g) 4000 n
8 Slide
Solving the task: 4. Which of the above statements are correct? A) The world's strength keeps the planet on their orbits around the sun b) The world's strength will change if you change the density of one of the attractive bodies B) with a free drop of a heavier body falls faster than the lighter, if they are reset from the same height d) if The body does not act on the body, the body is in a state of weightlessness.
Objectives of the lesson: to familiarize students with historical facts leading to the opening of the law of the World Committee, to study the areas of application of the law, its importance for science.
Tasks lesson:
Educational: to ensure assimilation by students of the physical meaning of the world of world gravity, gravitational constant, studying the formulas for accelerating the free fall and the speed of movement of satellites, to teach apply the law when solving problems.
Developing:
The development of cognitive interest with the use of historical materials and physical terms.
Development of the ability to see physical phenomena in the surrounding world.
Development of synthesizing thinking - the development of the ability to establish uniform, general signs and the properties of the whole, draw up the plan of the material studied, draw conclusions.
The formation of the skills to allocate the main thing is to draw up a plan, theses, to conduct abstracts.
Educational:
Education of the motives of teaching, positive attitude to knowledge.
Education of discipline.
The type of lesson is a lesson for studying a new material with elements of independent search and practical activity of students.
View of the lesson - conversation.
Equipment:
Multimedia system.
Presentation.
The lesson "Study of the nature of gravitational forces" is prepared for the 10th grades, but can be used in 9th grade when studying this topic, as well as on various electrical courses, thematic events.
Plan-chronometry lesson.
Stages lesson.
Takes and methods.
I. Organizational moment.
Motivation.
Conversation. Creating a positive attitude to educational activities. Control of the emotional state of students.
1. Staging a learning problem.
Conversation. The wording of goals and tasks of training sessions.
2. Organization of perception of educational material
Work with a presentation and textbook: Filling the support abstract (or notebook).
Homework.
Recording in supporting abstracts homework, His discussion and deadlines.
1. Summing up.
Generalization and systematization of completed work.
2. Mutual evaluation of work in the lesson.
Mark of absent on training lesson and estimates.
During the classes:
I. Organization of the beginning of the lesson.
Announcement of the lesson topics. Setting goals.
II. Studying a new material.
Why do all the bodies fall to the ground? This question has taken more ancient scientists. In antiquity, people considered the land with a plane, which relies the heavenly arch.
This presentation arose from a direct visual impression. Seeing that all the bodies on the earth's surface fall down, they decided that in the universe there is "top" and "bottom". That is why the bodies fall. Such a view was closely related to the concept of absolute "top" and "bottoms", quite coordinated with the views of the slave-owned society of the ancient world.
From the ancient sciences only at the end of the 13th century it was allowed to teach the teachings of the Greek philosopher Aristotle. However, this scientist has already been known, for example, that the Earth is a ball, and this contradicted the biblical look at the structure of the world. Therefore, the writings of Aristotle were equipped with various comments, leading to his teaching in consent to the Bible. Greek astronomers took all visible movements of cosmic bodies for valid. To explain the loop-shaped movement of the planets, the most complex geometric scheme was invented: the planet would be moving in a circle, the center of which turns around the Earth. Such was the system of the world of Greek astronoma Claudia Ptolemy, which was dominant in science until the mid-16th century.
In the 16th century, the Polish scientist Nikolai Copernicus decided to "wrap" the mechanism of the Universe. Is it easier to explain the difficult paths of the planets, if we assume that the earth describes the circular path around the sun? Nikolai Copernicus proved that the geocentric system of the world, (with land, as its center), nominated by the Greek scientist Claudius Ptolem and monopoloously dominated for almost one and a half thousand years, is incorrect. Copernicus belongs to the honor of creating modern ideas about the structure Solar system. Over the development of its system of the world, Copernicus worked all his life. He described it in the book "On the appeal of the heavenly spheres", which long did not decrease to publish not to bring the persecution of the Catholic Church. His book was published in 1543. She was a real revelation for scientists. She concluded the answer to those of them who
desperates thought that a person could not know the movements of heavenly shining and his knowledge of movements only in the "diluted" world, that is, on Earth. But the representations of Copernicus about the universe did not differ from what his contemporaries had.
In 1610, the entire cultural world was excited by an amazing news: Professor of the University in Padua made a pipe that could be seen in the sky, unknown stars and satellites of the planets. And the visual pipe directed towards the sky far spread the world's limits. Galilee was in a hurry to notify the whole world about the discoveries made them, making his famous "Star Bulletin". He told in it about the mountains, depressions, hills on the surface of the moon. "Star Bulletin" revealed the secret of the luminous Milky Way, which some ancient scientists were considered the place of "spikes" of crystal celestial areas. Finally, he informed the news of the new world of the planets - Jupiter, surrounded by satellites around him. But what power keeps the planet in orbits? This question then no one tried to answer.
Danish astronomer Tycho Brage headed the Uraniborg Observatory, which was built on the island of veins in the Ereinsunn Strait, near Copenhagen, and supplied with excellent tools made under his leadership. Here for 21 years he watched stars, planets and comets, producing definitions of provisions shone with quite high accuracy. This is his main merit. Braga did not recognize the heliocentric system of the world and in return to her offered another, representing the unsuccessful combination of the teachings of Ptolemy with the N. Copernicus system (the sun moves around the earth standing in the center of the Universe, and the planets - around the sun). In 1597, Braga was forced to leave Denmark (after his departure, the Uraniborg Observatory was abandoned) and after two years spent in Germany, moved to Prague. Here he entered the assistants I. Kepler, who, after the death of Braga, remained the most valuable observations.
In 1609, the German astronomer Johann Kepler, completing the work of Copernicus, managed to solve the secrets of the orbits, for which the planets move around the Sun, and their satellites - around the planets themselves. These orbits were not circles, as Copernicus believed, but ellipses.
As science developed, the man recognized and studied all the new forces acting in nature. However, without a doubt, the very first of the forces. famous person And the imagination hit his imagination, there was a force of gravity. Which of us did not fall on Earth under the action of this force, did not come across it every day, every moment? It is impossible to imagine life on Earth without the power of gravity.
But although the manifestations of the force of gravity are known to people as much time as they themselves exist, this force has been opened relatively recently, a little more than 300 years ago. In 1687, when the historical book of the great English scientific scientist Isaac Newton "Mathematical principles of natural philosophy" was published (then the science of nature, known now as physics, was then called).
To bring the laws of motion of the planets, it was necessary to know how the strength of gravity changes when the distance change. Newton suggested that the strength of gravity varies like the subject's lighting when approaching or removing from the light source: if the distance becomes three times more, the strength of gravity will decrease nine times, and vice versa. From the second law, the dynamics follows that the acceleration that the body receives under the action of force is inversely proportional to the mass of the body. But the acceleration of the free fall does not depend on body weight. This is only possible if the force with which the Earth attracts the body, changes in proportion to the mass of the body. According to the third law of force with which the bodies interact are equal. If the force acting on one body is proportional to the mass of this body, then the force equal to it acting on the second body is obviously proportional to the mass of the second body. But the forces acting on both bodies are equal, therefore, they are proportional to the mass of the first and second body. Newton calculated the ratio of the radius of the moon orbits to the radius of the Earth. The ratio was 60. And the ratio of the acceleration of the free fall on the ground to the centripetal acceleration, with which it turns around the Moon's Earth, was 3600. Consequently, the acceleration is inversely proportional to the square of the distance between the bodies. According to the second law, force and acceleration are associated with direct dependence, therefore, the force is inversely proportional to the square of the distance between the bodies.
For the first time, the gravitational constant was measured by the English physicist in the city of Cavendis in 1788 with the help of a device called twisted scales. G. Cavendish secured two small lead balls (with a diameter of 5 cm and weighing 775 g each) at the opposite ends of the two-meter rod. The rod was suspended on a thin wire. Two large lead balls (20 cm with a diameter and 45.5 kg) were close to small. The forces of attraction from large balls were forced to move small, while the wire was twisted. The degree of twisting was a measure of force acting between the balls. The experiment showed that gravitational G \u003d 6.67 * 10-11 N * m2 / kg2.
Created by Newton The theory of gravity tried one brilliant victory after another. It with a high degree of accuracy explained the features of planetary orbits found by Kepler. She managed to measure the masses of the planets, reveal the mysteries of the comet movement, secrets of tides. But, perhaps, the greatest triumph was the prediction of the non-discovery not yet made - the appearance of the Galeu comets in a given theory, the opening of unknown astronomers of planets and stars.
Accurate observations of the movement of the planet Uranus showed that this movement does not strictly obey Newton's law. It means that there is some kind of unknown reason that causes the deviation of the planet from the path intended to her theory. According to the calculations of the French scientist, the leverage came out that somewhere in the depths of the cosmos, then uranium, there must be another planet. And it was worth only to send a telescope in the point specified by the calculations (it happened in 1846), as an immediate stale asterisk, the desired asking for seeking an astronomer, immediately before looking for an eye! So Neptune was opened, and behind him and Pluto.
No less brilliantly solving the puzzle of Sirius, long-suffering astronomers. Sirius is the brightest star of our sky, she is in the constellation Big PSA, at a distance of 8.8 light years from the ground. More than 100 years ago it was noticed that Sirius was not moving in a straight line like almost all the other stars, but somehow strange, along a wavy curve. With the help of the theory of Newton, it was found that the "mystery" of Sirius's movement is related to the fact that it is not a simple, and a double star. Indeed, in this case, the center of masses of both stars would move, as it should be, in a straight line, and Sirius would deviate as a result of circulation around this center, then in one direction from the line, then to another, writing the wavy curve visible in the sky. Only 18 years after the theoretical prediction of the satellite asterisk, called Sirius-B, was actually found in the telescope. This happened in 1862.
The existence of the World Committee has been proven. But what is for power - worldwide gravity? Does she show herself on earth? And the Newton answered this question, tied in the same mathematical formula not only the movement of the planets, but also the fall of the stone on the earth's surface. Newton solved this task aged twenty-four years. At sea level and on the tops of the highest mountains - the bodies are falling due to gravity. "So maybe the phenomenon of gravity extends to the moon itself?" - I thought Newton and started checking my assumption. If so, then the moon movement can be compared with the kernel flying thrown out of the gun.
The more the core speed, the trajectory becomes more and more smooth and the kernel flies further. The mathematical calculation showed an amazing thing: if the velocity of the nuclei flight would reach 7906 meters per second, the curvature of the kernel trajectory would be the same with the curvature earth surface. Is there no moon, like this kernel, the power of gravity, which does not allow her to remove in a straight line to world space? That's what I decided to check Newton. To do this, it was necessary to calculate how large the power of gravity at the distance of the moon from the ground. The effect of gravity at the distance of the moon turned out to be the same with the action of global gravity. So the strength of gravity and the world gravity is the same force.
It seemed that Newton's theory was unshakable for centuries. After all, even now, when science storms space, the movement of satellites, cosmic missiles - with great accuracy calculated precisely with the help of Newton's theory.
A satellite can be any body if it informs the necessary speed in this height, directed perpendicular to the radius of the Earth.
The speed that must be reported to the body so that it becomes a satellite of the planet is called the first space speed.
And yet, in the essence of this theory, its indigenous vices were concluded. No matter how accurate theory, it is not able to answer the fatal question: what is the origin of the power of gravity, what is its nature? The author of Isaac Newton himself admitted his powerlessness, saying: "I could not bring out the cause of the properties of the power of gravity, I do not inform the hypothesis."
What was not managed by Newton did another great scientist - Albert Einstein. In 1916, he published his famous general theory of relativity, containing radically new ideas about the nature of the nature. On its basis, he created a new picture of the universe. Einstein's theory "I absorbed" Newton's law, sowing and immeasurably, she explained not to some special force acting on the part of massive bodies, the sun, etc., and the features of space near such bodies.
For the first time, science managed to explain the nature of the origin. Newton fully allowed an abstract theoretical possibility of the existence of a space in which there is no matter in general and there is really no theoretically, so there is a free movement on inertia is actually straight and evenly. Einstein believed that it was impossible in principle. According to his theory without matter, there simply does not exist either space or time. Once upon a time the question of the reporter about what, in the most brief form, The essence of the general theory of relativity, Einstein replied: "It was previously believed that if all the matter had disappeared from the universe, then the space and time would be preserved. The theory of relativity argues that the space and time will also disappear with matter. " The space in the field of gravity, as Einstein said, "twisted" - this is exactly the curvature and there is a manifestation of gravity, and there is itself.
III. Reflective-estimated stage of the lesson.
Summarizing.
Mutual evaluation of work in the lesson.
List of references and sources used.
1. Textbook "Physics Grade 10. A basic level of", N.S. Purysheva, N.E. Vaseevskaya, D.A. Isaev, Moscow, Drop, 2010
2. Physics 10 class. Myakyshev G.Ya., Bukhovtsev B.B., Sotsky N.N. M.: Enlightenment, 2008
3. V.A. Volkov Pounding development in physics. 9th grade. Moscow "Vako", 2005
Similar educational materials:
Slide 1.
Solving tasks. Gravitational forces. 9-10 class.Clade 2.
Does the strength of attraction to the sun act on a person? How to explain the occurrence of tides and tissions in the ocean? Explain the physical meaning of the gravitational constant? Frontal survey of students:
Slide 3.
How many times will the force of attraction between bodies with an increase in the distance between them 5 times? A. will increase 5 times; B. decreases 5 times; C. decreases 25 times. 2. How many times will the force of attraction between the bodies with a decrease in the mass of each body 2 times? A. will increase by 2 times; B. decrease 4 times; C. will decrease by 4 times. Task:
Slide 4.
3. How many times will the force of attraction between the bodies, with an increase in the distance between them 2 times and the increase in the mass of one of them 4 times? A. It will increase by 8 times B. Changes C. will decrease by 2 times how many times will change the force of attraction between bodies with a decrease in the mass of one of the bodies 2 times and increasing the distance between them 2 times? A. It will increase by 2 times B. It will decrease by 4 times C. It will decrease 8 times
Slide 5.
Solving the task: 1. At the astronaut, which is on the surface of the Earth, the strength of 720 N. What is the strength of grave to act on the same astronaut in a spacecraft located at a distance of two terrestrial radii from the surface of the Earth? A) 180 H b) 80 N c) 360 nd) 240
Slide 6.
Task: 2. Two bodies weighing 103 kg and 2 · 103 kg are from each other at a distance of R and are attracted with force F. What is the force of attraction of bodies weighing 2 · 103 kg and 4 · 103 kg, located at the same distance R ? A) f b) 2f c) 4f g) 8f
Slide 7.
Task: 3. On the surface of the Earth on the astronaut in the scaffle, the strength of gravity 1000 N. on the surface of the planet with a radius is 2 times less than the earth and weighing 2 times less than the mass of the Earth, the strength of gravity acting on this astronaut will be equal to: a) 500 N B) 1000 N c) 2000 n g) 4000 n
Slide 8.
Solving the task: 4. Which of the above statements are correct? A) The world's strength keeps the planet on their orbits around the sun b) The world's strength will change if you change the density of one of the attractive bodies B) with a free drop of a heavier body falls faster than the lighter, if they are reset from the same height d) if The body does not act on the body, the body is in a state of weightlessness.
9-10 class.
Does the strength of attraction to the sun act on a person?
How to explain the occurrence of tides and tissions in the ocean?
Explain the physical meaning of the gravitational constant?
How many times will the force of attraction between bodies with an increase in the distance between them 5 times?A.Will increase 5 times;
B.Will decrease 5 times;
C.Decrease 25 times.
2. How many times will the force of attraction between the bodies with a decrease in the mass of each body 2 times?A.. Will increase by 2 times;
B.. Will decrease by 4 times;
C.. It will decrease by 4 times.
3. How many times will the force of attraction between the bodies, with an increase in the distance between them 2 times and the increase in the mass of one of them 4 times? A.. Will increase 8 times
B.. Will not change
C.. Decrease by 2 times
How many times will the force of attraction between the bodies change with a decrease in the mass of one of the bodies 2 times and increase the distance between them 2 times?
A.. Will increase by 2 times
B.. Will decrease by 4 times
C.. Decrease 8 times
1. On the astronaut on the surface of the Earth, the strength of 720 N. What is the strength of gravity on the same astronaut in a spacecraft located at a distance of two earth radii from the ground surface?
A) 180 H b) 80 N c) 360 nd) 240
2. Two bodies weighing 103 kg and 2 · 103 kg are apart from each other at a distance of R and attract with force F. What is the force of attraction of bodies weighing 2 · 103 kg and 4 · 103 kg, located at the same distance r?
A) f b) 2f c) 4f g) 8f
3. On the surface of the earth on the astronaut in the Space, the strength of gravity is 1000 N. on the surface of the planet with radius 2 times less ground and weighing 2 times less than the mass of the Earth, the strength of gravity acting on this astronaut will be equal to.
