Поиск по:www.cosmos.ru -
Поискать по всем серверам
На этой странице приведены все страницы сервера www.cosmos.ru ,которые мы индексируем. Показаны документы 1701 - 1720 из 10690.
Упорядочить по:
URL
|
дате изменения
1701. Work against an Electric Force
... 18c. Work . ... Electric Forces . ... Ordinary matter consists of negative electrons and positive atomic nuclei , and their electric charges attract each other. ... In 1929 Robert Van de Graaff in Princeton found a new way of charging a hollow sphere to high voltages. ... What happens is that by pulling the sheets apart, you had to perform work against the electric force, and that raised the voltage of the electric charge, just as in thundercloud ice and in the Van de Graaff generator. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Svandgrf.htm -- 19.5 Кб -- 22.12.2007
Похожие документы
Похожие документы
1702. The Angle of the Sun's Rays
... 3a. Angle . of sunlight . ... The Moon (1) . ... 4b. Moon Libration . ... The apparent path of the Sun across the sky. Note how much higher the Sun is in the sky in mid-summer! ... In addition, they are invariably tilted at an angle around 45 , to make sure that the arrival of the sun's rays is as close to perpendicular as possible. ... The rays of the summer sun, high in the sky, arrive at a steep angle and heat the land much more than those of the winter sun, which hit at a shallow angle. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sunangle.htm -- 9.1 Кб -- 22.12.2007
Похожие документы
Похожие документы
1703. (S-7) The Energy of the Sun
... The Sun . ... S-7.The Sun's Energy . ... of Atoms and Nuclei . S-8.Nuclear Power . ... The Sun is the source of most of the energy on Earth--the power source for plants, the cause of flows of atmosphere and of water, the source of the warmth which makes life possible. ... The electric force may be weaker than the nuclear force, but its range is greater: in an iron nucleus, each proton repels 25 other nuclei, while (one may argue) the nuclear force only binds close neighbors. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sun7enrg.htm -- 32.4 Кб -- 22.12.2007
Похожие документы
Похожие документы
1704. (S-5) Waves and Photons
... S-5.Waves Photons . ... It is therefore possible to extract from its light just one narrowly defined color--a single spectral line--and still have enough brightness left to give a detailed picture. ... Light and radio waves belong to the electromagnetic spectrum, the range containing all different electromagnetic waves. ... It is only brought up because of its claim that the amount of energy which an atom can receive from an electromagnetic wave--its photon--depends only on that wave's length. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sun5wave.htm -- 21.6 Кб -- 22.12.2007
Похожие документы
Похожие документы
1705. The Many Colors of Sunlight
... Colors of Sunlight . ... Isaac Newton showed that not only can a triangular prism separate a beam of sunlight into rainbow colors (that had already been known), but also that, when a second prism brings the different colors together again, white light is once more obtained. Therefore white light is a combination of all the rainbow colors, and the prism separates its colors because the angle by which a beam of light is bent, when it enters glass, differs from one color to the next. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sun4spec.htm -- 19.8 Кб -- 22.12.2007
Похожие документы
Похожие документы
1706. Sunlight and the Earth
... Sunlight Earth . ... Life as we know it needs liquid water, and Earth is the only planet to have it: without the Sun, Earth would be an icy rock in space. ... As the ground is heated by sunlight, it begins to radiate, but being too cool to radiate even a dull red, its radiation is in the infra-red range. ... Clouds in the atmosphere reflect some of the sunlight before it reaches the ground, reducing the heating of the ground. ... Air can flow, and thus carry its heat from one place to another. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sun1lite.htm -- 19.1 Кб -- 22.12.2007
Похожие документы
Похожие документы
1707. Starships
... In a game of ping-pong, suppose a paddle moves at 20 miles per hour and hits a ball with 20 mph in the opposite direction. ... In the new problem, a ball moving at -40 mph hits a non-moving surface; if the collision is elastic (no energy lost), that ball returns with the same speed but in the opposite direction, i.e. its velocity reverses sign. ... Something very similar happens when a spacecraft with velocity v passes close to a moving planet and is deflected. ... Could Earth capture a second moon?...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Stostars.htm -- 13.7 Кб -- 22.12.2007
Похожие документы
Похожие документы
1708. "Stargazers" in the Classroom
... From Stargazers to Starships" is meant as an introduction to space, both for the inquisitive non-scientist and for students and teachers in schools. ... The motion of the Earth in space (e.g. why summers are hot, winters cold), and . ... Stargazers (sections 1-12)--a study of the Earth's motion in space and of the solar system to which it belongs, almost entirely in the framework of pre-telescope astronomy. ... Distance of the Moon (8b-d). ... the transport of heat from the Sun-heated Earth to space...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Steacher.htm -- 19.6 Кб -- 22.12.2007
Похожие документы
Похожие документы
1709. "Stargazers" and National Science Standards
... The material in "From Stargazers to Starships" meets several important requirements of the national standards. Pages cited below are from National Science Education Standards National Academy Press, Washington 1995. ... For example: the sections on astronomy not only describe calendars and sundials (including their construction), but also the astronomy of the ancient Greeks, including two different ways in which ancient Greeks estimated the distance to the Moon. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Standrds.htm -- 7.9 Кб -- 22.12.2007
Похожие документы
Похожие документы
1710. Rotating Frames of Reference in Space and on Earth
... 24a.The Rotating Earth . 24b. Rotating Frames . ... That can be interpreted as stating that in the astronaut's frame of reference, all bodies are subject to two forces, gravity and the centrifugal force, and the two are in perfect balance, adding up to zero. ... Viewing the astronaut's motion in the frame of the moving spacecraft, the astronaut is not pulled towards the floor of the cabin or in any other direction, and therefore has the impression that gravity has been eliminated. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Srotfram.htm -- 18.3 Кб -- 22.12.2007
Похожие документы
Похожие документы
1711. The Evolution of Rockets
... The full story of rocket technology is too long to be covered here. ... Some of the experiments used liquid fuel, though solid-fuel rockets were also developed. ... Karm n . ... Apart from the V-2, the various armies in WW II used solid-fuel artillery rockets much in the way that Congreve had used them, for massive bombardments, to cover attacks or beach landings; the Russian army, for instance, had its famed "Katyusha". The X-1 rocket airplane, the first . ... are seen in the rocket exhaust. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Srockhis.htm -- 16.0 Кб -- 22.12.2007
Похожие документы
Похожие документы
1712. Problems--Second Installment
... It is much larger than the planets of the solar system--about 65 times the mass of Jupiter, orbiting at a distance somewhat greater than Jupiter's. Still, it is probably too small to produce heat like the Sun and shine with its own light; the only way to see the planet (you can assume) is by the light of its own sun, reflected from it, the way the Moon is seen. ... 4a] Viewed from Earth, the Sun, Moon and stars rise and set with various periodicities, all of them close to 24 hours. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sproblm2.htm -- 40.2 Кб -- 22.12.2007
Похожие документы
Похожие документы
1713. Problems
... You note that the Earth orbits around the Sun in a counterclockwise direction. ... 7] In one of the eclipses of 1999 the Moon is unable to cover the entire Sun. ... If an object were to be placed in the Earth orbit but with no velocity relative to the Sun, it would fall sunward. ... You may assume that the width of the Earth is 3.5 times that of the Moon (see problem 15), that the Moon is 60 Earth radii from the center of Earth and that, as seen from Earth, it is equal in size to the Sun. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sproblem.htm -- 24.4 Кб -- 22.12.2007
Похожие документы
Похожие документы
1714. Precession
... The Round Earth . ... 9a. Earth orbits Sun? . ... Comparing observations more than a century apart, Hipparchus proposed that the axis around which the heavens seemed to rotate shifted gradually, though very slowly. Viewed from Earth, the Sun moves around the ecliptic, one full circuit each year. ... During an eclipse, Sun, Earth and Moon form a straight line, and therefore the center of the Earth's shadow is at the point on the celestial sphere which is exactly opposite that of the Sun. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Sprecess.htm -- 21.6 Кб -- 22.12.2007
Похожие документы
Похожие документы
1715. Finding the Pole Star
... 1b. Pole Star . ... Two bright constellations occupy opposite sides of the pole star--the Big Dipper and Cassiopeia . ... The Big Dipper consists of 7 bright stars, forming a dipper, a small pot with a long handle. ... It shows the 7 stars of the Big Dipper and Polaris, the north star. ... Ursa Minor , the "Small Bear" or "Little Dipper" is a constellation somewhat resembling the Big Dipper, and Polaris is the last star in its tail. ... Questions from Users: About the stars of the Big Dipper . ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Spolaris.htm -- 11.9 Кб -- 22.12.2007
Похожие документы
Похожие документы
1716. Spaceflight
... This realization, in the years after World War II, turned the military into a major supporter of rocket development, especially in the US and in the USSR, the Soviet Union (now the Russian republic and its allies). ... launched the Sputniks. ... Today all space launches employ clamps to hold the rocket down during those seconds, until full thrust is achieved; if you ever watch the countdown of a spaceflight launch, you might note that "ignition" comes a short instant before "lift-off. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Spacefly.htm -- 14.4 Кб -- 22.12.2007
Похожие документы
Похожие документы
1717. (S-9) Nuclear Weapons
... The preceding web page on nuclear power, written two years ago, deliberately avoided the subject of weapons. ... S-9.Nuclear Weapons . ... However, it also has a second aspect--the making of nuclear bombs . Instead of gradually "burning up" U235 or plutonium (the main nuclear fuels), producing heat for generating electricity, a bomb releases its energy very abruptly, creating an intense concentration of heat. ... Even given purified fuel, it is not easy to build a nuclear bomb . ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Snucweap.htm -- 17.9 Кб -- 22.12.2007
Похожие документы
Похожие документы
1718. (S-8) Nuclear Energy
... Note: This is a side-excursion into the basics of nuclear energy , beyond the main scope of "from Stargazers to Starships." ... S-8.Nuclear Power . ... Here some facts about the way protons and neutrons combine to form nuclei, as covered in section S-7 about the Sun: . ... In even heavier nuclei, we find energy is lost, not gained by adding protons. ... The fuel is uranium 235 (U-235)--a variant ("isotope") with 92 protons but only 143 neutrons, not 146, an odd number which makes it less stable. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Snuclear.htm -- 29.4 Кб -- 22.12.2007
Похожие документы
Похожие документы
1719. Newton's 3rd Law
... Newton's Laws . ... If object A exerts a force F on object B, . then object B exerts an equal and opposite force ?F on object A" . ... There exists a whole set of situations where two equal and opposite forces act on the same object, canceling each other so that no acceleration (or even no motion) occurs. ... It is all in Newton's third law: as your legs propel your body towards the dock, they also apply to the boat an equal force in the opposite direction, which pushes it away from the dock. ...
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Snewton3.htm -- 12.1 Кб -- 22.12.2007
Похожие документы
Похожие документы
1720. Newton's Second Law
... Newton's Laws . ... Mass . ... The most familiar force is weight, the downward force on an object due to gravity. ... In the absence of opposing forces, if a force does act on an object at rest or moving at constant speed, it accelerates in the direction of the force. ... By Newton's second law, the acceleration a of an object is proportional to the force F acting on it and inversely proportional to its mass m. Expressing F in newtons we now get a --for any acceleration, not just for free fall--as ....
[
Сохраненная копия
]
Ссылки http://www.cosmos.ru/mirrors/stern/stargaze/Snewt2nd.htm -- 14.4 Кб -- 22.12.2007
Похожие документы
Похожие документы