Scientists from different countries have used radar to determine the distance to Mercury, Venus, Mars and Jupiter.

Scientists from different countries have used radar to determine the distance to Mercury, Venus, Mars and Jupiter.

The C-6A aircraft had good flight characteristics, its takeoff weight reached 1,100 kg, payload – 450 kg, on it II Sikorsky flew with four passengers.

This model brought the designer well-deserved fame. At the Moscow Aeronautical Exhibition, the designer was awarded the Grand Gold Medal, and the Russian Technical Society awarded him the medal "For useful work in aeronautics and for self-development of the airplane of its system, which gave excellent results."

In April 1912, II Sikorsky, who was only 22 years old, was invited to the position of chief designer of the aviation department of the Russian-Baltic Carriage Plant. Many original aircraft were born at this enterprise, which gained the recognition of specialists not only in Russia but also abroad: the S-6B aircraft (1912), the S-10 biplane, and the S-11 monoplane (1913). II Sikorsky’s C-7 aircraft was sold abroad for the first time. Training and training machines, seaplanes were also developed.

The new stage of activity of II Sikorsky-designer is connected with his transition to another direction of aviation – heavy aircraft construction. In the spring of 1913, a fundamentally new Russian Knight aircraft was built, which was several english lab report writing service times larger and heavier than all known aircraft. It was a giant biplane equipped with four engines, with a large enclosed cockpit and a comfortable passenger cabin.

On December 10, 1913, the famous "Ilya Muromets" real airship took to the air. It had a comfortable passenger cabin with electric lighting, the area of ​​its wings was three times larger than the "Russian Knight". In 1914, the world record for carrying capacity was set at Ilya Muromets.

On the second "Ilya Muromka" the crew led by II Sikorsky made a unique flight St. Petersburg – Kiev and back. The Kyiv Society of Aeronauts awarded the famous compatriot a gold medal with the inscription "To the Glorious Knight of the Russian Air Ocean Igor Sikorsky". The army praised "Ilya Muromets" as a unique means of long-range reconnaissance and bombing, and the Baltic plant received an order to produce aircraft of this type.

During the First World War, "Murom" new modifications went into series, they were created by a squadron, which operated effectively at the front. During the war, II Sikorsky created several other types of aircraft: light type interceptor fighter, reconnaissance, escort fighters, attack aircraft and other types. In fact, the foundations of the Russian aviation industry were laid.

After the revolution of 1917, production at the Russian-Baltic Carriage Plant declined, supplies were disrupted, and no orders were received. II Sikorsky was forced to leave the plant. He was invited to continue working in France. In January 1918 he sailed from Murmansk abroad.

After a short stay in France, where at the end of the war the need for his design talent was exhausted, II Sikorsky moved to the United States and there four years later with a group of Russian emigrants organized an aircraft company. Operation of the first S-29A aircraft built in the United States on the basis of Ilya Muromets (1924) made it possible to strengthen the company’s position. In the 1920s, a series of II Sikorsky’s aircraft of various types was built.

In the late 1920’s, II Sikorsky’s firm became part of the powerful aviation corporation United Aircraft and Transport Corporation. His design activities received new incentives for development. Work on the creation and improvement of aircraft continued. Some of these devices have become widely known. Thus, the S-42 set ten world records, and ten production S-42s became the world’s first intercontinental passenger liners to provide regular flights across the Atlantic and Pacific Oceans.

In the late 1930’s, II Sikorsky switched to the creation of helicopters. For two decades, he designed helicopters of various classes, which became widespread. His company, which became independent again in 1943, was a leading manufacturer of helicopters. From the production of II Sikorsky’s helicopters began serial helicopter construction not only in the United States but also in Great Britain and France.

After retiring in 1957 and until his death, II Sikorsky remained a consultant to the firm. With his participation, second-generation helicopters were created and the development of third-generation helicopters began.

12.08.2011

Solar system: determination of body sizes and distances, gravity. Abstract

The abstract provides information on the determination of distances and sizes of bodies in the solar system, and the motion of celestial bodies under the action of gravity

Determination of distances and sizes of bodies in the solar system

The solar system consists of a center, a luminary – the Sun and 9 large planets orbiting it, their satellites, many small planets, comets and meteorite particles (interplanetary gunpowder). The Sun’s rotation around the Galaxy’s axis moves at a speed of about 240 km / s, so it makes one complete rotation in about 200 million years.

Determination of distances

The average distance of all planets from the Sun in astronomical units can be calculated using Kepler’s third law. Since the 1940s, radio engineering has made it possible to determine distances to celestial bodies using radar. Scientists from different countries have used radar to determine the distance to Mercury, Venus, Mars and Jupiter.

The classical method of determining distances was and remains the angular geometric method. They determine the distances to distant stars to which the radar method cannot be applied. The geometric method is based on the phenomenon of parallax displacement. Parallactic displacement is a change in the direction of the object when the observer is displaced. To measure the distances to the bodies of the solar system, it is convenient to take the radius of the Earth as a basis.

Observe the position of light, such as the moon, against the background of distant stars simultaneously from two observatories. The distance between the observatories can be as large as possible, and the segment connecting them should form an angle with the direction of the luminary, as close as possible to a straight line, so that the parallactic displacement was maximum. Having determined from two points A and B the directions to the observed object, it is easy to calculate the angle p, at which from this object would be visible a segment equal to the radius of the Earth. So, to determine the distances to celestial bodies, you need to know the value of the base – the radius of our planet.

The size and shape of the Earth

In photographs taken from space, the Earth has the appearance of a sphere illuminated by the Sun, and shows the same phases as the Moon. The exact answer about the shape and size of the Earth is given by degree measurements, in kilometers of arc length 1˚ in different places on the Earth’s surface. This method in the III century. BC e. Used by the Greek scientist Eratosthenes. Now this method is used in geodesy – the science of the shape of the Earth and the measurement on Earth based on its curvature.

On level ground, select two points lying on the same meridian, and determine the length of the arc between them in degrees and kilometers. Then calculate how many kilometers corresponds to the length of the arc 1˚. It is clear that the length of the arc of the meridian between the selected points in degrees is equal to the difference of latitudes of these points. If the length of this arc, measured in kilometers, is equal to l, then at the sphericity of the Earth 1˚ of the arc will correspond to the length in kilometers. Then the length of the circle of the earth’s meridian L, expressed in kilometers, is equal to L = 360˚n. Dividing it by 2P, we get the radius of the Earth.

One of the largest arcs of the meridian from the Arctic Ocean to the Black Sea was measured in Russia and Scandinavia in the mid-nineteenth century. under the direction of V. Ya. Struve, director of the Pulkovo Observatory. The sphere, equal to our planet, has a radius of 6,370 km. This value is considered the radius of the Earth. Earth is the third planet from the sun in the solar system, which revolves around the sun in an elliptical orbit at a speed of 29.705 km / s at an average distance of 149.6 million km, which is a period equal to 305.27 average solar days. The average distance from the earth to the sun, light passes in 8 hours 19 seconds.

Rotation around the axis causes a change of day and night, the tilt of the axis and orbit around the sun causes a change of seasons. The shape of the Earth is approximately – a three-axis ellipsoid. The average radius of the Earth is 6371.032 km, the equatorial 6378.106 km, the polar 6356.777 km, the surface area is 510.2 million square kilometers; volume 1, average density 5518 kg / m cubic. The earth has magnetism and is closely connected with the electric field.

The Earth’s gravitational field forms a spherical shape of the Earth. The idea of ​​the Earth was formulated about 4.7 billion years ago. As a result of the influence of the gravitational field on the Earth, and in the conditions of heating of the earth’s interior, different in chemical composition, physical state and physical properties of the shell-geosphere arose and developed:

core, mantle, crust, hydrosphere, atmosphere, magnetosphere.

The Earth contains:

iron (34.6%), silicon (15.2%), magnesium (12.7%).

The earth’s crust, mantle and inner core are solid. From the Earth’s surface to the center, pressure, density, and temperature increase. Most of the Earth’s surface is covered by the world’s oceans. It rises above sea level by 875 m, the desert occupies about 20% of the land surface. The average depth of the ocean is about 3800 m. The Earth’s atmosphere consists of air – mixed with nitrogen and oxygen, everything else is water vapor, carbon dioxide, inert and other gases.

Parallax. The value of the astronomical unit

The angle at which the Earth’s radius perpendicular to the line of sight is visible from light is called horizontal parallax. The horizontal parallax of the Moon is 57΄. All planets and the Sun are much more distant, and their parallaxes are seconds of arc. The parallax of the Sun, for example, is 8.8˝. The parallax of the sun corresponds to the average distance of the Earth from the Sun, which is approximately 150,000,000 km. This distance is taken as one astronomical unit (1 AU). in astronomical units, the distance between the bodies of the solar system is often measured.

The movement of celestial bodies under the action of gravity

Cosmic velocities and the shape of orbits. Based on observations of the Moon’s motion and analyzing Kepler’s laws of planetary motion, Newton established the law of universal gravitation. According to this law, all bodies in the universe are attracted to each other with a force directly proportional to the square distance between them. This law explains the motion of planets and comets around the Sun, the motion of satellites around planets.