The acceleration due to gravity at the Earth's surface, denoted g, is approximately 9.8 m/s2 (metres per second squared) or 32 ft/sec2. This means that, ignoring air resistance, an object falling freely near the earth's surface increases in speed by 9.8 m/s (around 22 mph) for each second of its descent. Thus, an object starting from rest will attain a speed of 9.8 m/s after one second, 19.6 m/s after two seconds, and so on. The earth itself experiences an equal and opposite force to that of the falling object, m ...

See also:

Gravity, Gravity - Overview of the history of gravitational theory, Gravity - Newton's law of universal gravitation, Gravity - Acceleration due to gravity, Gravity - Bodies with spatial extent, Gravity - Vector form, Gravity - Gravitational field, Gravity - The Earth's gravity, Gravity - Comparative gravities of the Earth Sun Moon and planets, Gravity - Mathematical equations for a falling body, Gravity - Gravitational potential, Gravity - Acceleration relative to the rotating Earth, Gravity - Gravity and astronomy, Gravity - Self-gravitating system, Gravity - Practical uses of gravity, Gravity - Problems with Newton's theory, Gravity - Theoretical concerns, Gravity - Disagreement with observation, Gravity - Newton's reservations, Gravity - Einstein's theory of gravitation, Gravity - Experimental tests, Gravity - Comparison with electromagnetic force, Gravity - Gravity and quantum mechanics, Gravity - Alternative theories, Gravity - Recent alternative theories, Gravity - Historical alternative theories, Gravity - Notes

Read more here: » Gravity: Encyclopedia II - Gravity - The Earth's gravity

See also:

Gravity, Gravity - Overview of the history of gravitational theory, Gravity - The Earth's gravity, Gravity - Comparative gravities of the Earth Sun Moon and planets, Gravity - Mathematical equations for a falling body, Gravity - Gravitational potential, Gravity - Acceleration relative to the rotating Earth, Gravity - Gravity and astronomy, Gravity - Self-gravitating system, Gravity - Practical uses of gravity, Gravity - Newton's law of universal gravitation, Gravity - Acceleration due to gravity, Gravity - Bodies with spatial extent, Gravity - Vector form, Gravity - Gravitational field, Gravity - Problems with Newton's theory, Gravity - Theoretical concerns, Gravity - Disagreement with observation, Gravity - Newton's reservations, Gravity - Einstein's theory of gravitation, Gravity - Experimental tests, Gravity - Comparison with electromagnetic force, Gravity - Gravity and quantum mechanics, Gravity - Alternative theories, Gravity - Recent alternative theories, Gravity - Historical alternative theories, Gravity - Notes

Read more here: » Gravity: Encyclopedia II - Gravity - The Earth's gravity

Thee acceleration due to gravity at the Earth's surface, denoted g, is approximately 9.8 m/s2 (metres per second squared) or 32 ft/sec2. This means that, ignoring air resistance, an object falling freely near the earth's surface increases in speed by 9.8 m/s (around 22 mph) for each second of its descent. Thus, an object starting from rest will attain a speed of 9.8 m/s after one second, 19.6 m/s after two seconds, and so on. The earth itself experiences an equal and opposite force to that of the falling object, ...

See also:

Gravity, Gravity - Overview of the history of gravitational theory, Gravity - Newton's law of universal gravitation, Gravity - Acceleration due to gravity, Gravity - Bodies with spatial extent, Gravity - Vector form, Gravity - Gravitational field, Gravity - The Earth's gravity, Gravity - Comparative gravities of the Earth Sun Moon and planets, Gravity - Mathematical equations for a falling body, Gravity - Gravitational potential, Gravity - Acceleration relative to the rotating Earth, Gravity - Gravity and astronomy, Gravity - Self-gravitating system, Gravity - Practical uses of gravity, Gravity - Problems with Newton's theory, Gravity - Theoretical concerns, Gravity - Disagreement with observation, Gravity - Newton's reservations, Gravity - Einstein's theory of gravitation, Gravity - Experimental tests, Gravity - Comparison with electromagnetic force, Gravity - Gravity and quantum mechanics, Gravity - Alternative theories, Gravity - Recent alternative theories, Gravity - Historical alternative theories, Gravity - Notes

Read more here: » Gravity: Encyclopedia II - Gravity - The Earth's gravity

Gravity is a force of attraction that acts between bodies that have mass. It is a physical phenomenon of fundamental importance, profoundly affecting the workings of the world around us and the universe beyond. Most familiarly, it is the gravitational attraction of the earth that endows objects with weight and causes them to fall to the ground when dropped. In fact, gravity is also the reason for the very existence of the earth, the sun and other celestial bodies; without it matter would not have coalesced into these bodies and ...

Including:

Gravity - Overview of the history of gravitational theory Gravity - Newton's law of universal gravitation
Gravity - Acceleration due to gravity Gravity - Bodies with spatial extent Gravity - Vector form Gravity - Gravitational field
Gravity - The Earth's gravity
Gravity - Comparative gravities of the Earth Sun Moon and planets
Gravity - Mathematical equations for a falling body
Gravity - Gravitational potential Gravity - Acceleration relative to the rotating Earth
Gravity - Gravity and astronomy
Gravity - Self-gravitating system
Gravity - Practical uses of gravity Gravity - Problems with Newton's theory
Gravity - Theoretical concerns Gravity - Disagreement with observation Gravity - Newton's reservations
Gravity - Einstein's theory of gravitation
Gravity - Experimental tests
Gravity - Comparison with electromagnetic force Gravity - Gravity and quantum mechanics Gravity - Alternative theories
Gravity - Recent alternative theories Gravity - Historical alternative theories
Gravity - Notes

Read more here: » Gravity: Encyclopedia - Gravity

Thee acceleration due to gravity at the Earth's surface, denoted g, is approximately 9.8 m/s2 (metres per second squared) or 32 ft/sec2. This means that, ignoring air resistance, an object falling freely near the earth's surface increases in speed by 9.8 m/s (around 22 mph) for each second of its descent. Thus, an object starting from rest will attain a speed of 9.8 m/s after one second, 19.6 m/s after two seconds, and so on. The earth itself experiences an equal and opposite force to that of the falling object, ...

See also:

Gravity, Gravity - Overview of the history of gravitational theory, Gravity - The Earth's gravity, Gravity - Comparative gravities of the Earth Sun Moon and planets, Gravity - Mathematical equations for a falling body, Gravity - Gravitational potential, Gravity - Acceleration relative to the rotating Earth, Gravity - Gravity and astronomy, Gravity - Self-gravitating system, Gravity - Practical uses of gravity, Gravity - Newton's law of universal gravitation, Gravity - Acceleration due to gravity, Gravity - Bodies with spatial extent, Gravity - Vector form, Gravity - Gravitational field, Gravity - Problems with Newton's theory, Gravity - Theoretical concerns, Gravity - Disagreement with observation, Gravity - Newton's reservations, Gravity - Einstein's theory of gravitation, Gravity - Experimental tests, Gravity - Comparison with electromagnetic force, Gravity - Gravity and quantum mechanics, Gravity - Alternative theories, Gravity - Recent alternative theories, Gravity - Historical alternative theories, Gravity - Notes

Read more here: » Gravity: Encyclopedia II - Gravity - The Earth's gravity

The actual acceleration of a body at the Earth's surface depends on the location at which it is measured, smaller at lower latitudes, for two reasons. The first is that the rotation of the Earth imposes an additional acceleration on the body that opposes gravitational acceleration. The net downward force on the body is therefore offset by a centrifugal force that acts upwards, reducing its weight. This effect on its own would result in a range of values of g from 9. ...

See also:

Gee, Gee - Variations of Earth's gravity, Gee - Calculated value of g, Gee - Usage of the unit, Gee - Human g-force experience, Gee - Strongest g-forces survived by humans, Gee - Reference

Read more here: » Gee: Encyclopedia II - Gee - Variations of Earth's gravity

In physics, an orbit is the path that an object makes around another object while under the influence of a source of centripetal force, such as gravity. Planetary orbit - History. Orbits were first analysed mathematically by Johannes Kepler who formulated his results in his three laws of planetary motion. First, he found that the orbits of the planets in our solar system are elliptical, not circular (or epicyclic), as had previously been believed, and that the sun is not located at the center of the orbits, ...

Including:

Planetary orbit - History Planetary orbit - Planetary orbits Planetary orbit - Understanding orbits Planetary orbit - Newton's laws of motion Planetary orbit - Analysis of orbital motion Planetary orbit - Orbital parameters Planetary orbit - Orbital period Planetary orbit - Orbital decay Planetary orbit - Earth orbits Planetary orbit - Scaling in gravity Planetary orbit - Role in the evolution of atomic theory

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Weightlessness is the experience (by people and objects) during freefall, of having no apparent weight. This condition is also known as microgravity (see below). Weightlessness in common spacecraft is not due to an increased distance to the earth; the acceleration due to gravity at an altitude of 100 km is only 3% less than at the surface of the earth. Weightlessness means a zero g-force or zero apparent weight; acceleration is only due to gravity, as opposed to the cases where other forces are acting, including: s ...

Including:

Weightlessness - Overview Weightlessness - Microgravity Weightlessness - NASA's KC-135 Reduced Gravity Aircraft Weightlessness - Zero Gravity Corporation Weightlessness - NASA's Zero-G Research Facility Weightlessness - Weightlessness in a spaceship Weightlessness - Weightlessness in the centre of a planet Weightlessness - Health effects

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Constrain is a verb that means to limit or restrict a process. The earths movement is constrained by the sun's gravity (and other forces). The project was constrained by a shortage of funds. Her hopes were constrained by her sense of realism. Other related archivesproject

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GEM is an acronym for: Genetically Engineered Microorganism Global Electric Microcars Graphical Environment Manager — a windowing system created by Digital Research, Inc. (DRI) Graphics Environment for Multimedia, a Pure data package for 3D graphics Grenoble Ecole de Management, the Grenoble Graduate School of Management Globally Executable MHP Goddard Earth Model - A model of the Earth's gravity field Gravitoelectromagnetism - deals with the theory of field ...

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The Aristotelian theory of gravity was that all bodies move towards their natural place. For some objects, Aristotle claimed the natural place to be the center of the earth, wherefore they fall towards it. For other objects, the natural place is the heavenly spheres, wherefore gases, steam for example, move away from the center of the earth and towards heaven and to the moon. The speed of th ...

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Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. The gases are attracted by the gravity of the body, and held fast if gravity is sufficient and the atmosphere's temperature is low. Some planets consist mainly of various gases, and thus have very deep atmospheres (see gas giant). Earth, Venus, Mars, and Pluto have atmospheres that envelop their surfaces, as do three of the satellites of the outer planets: Titan, Enceladus (moons of Saturn), and Triton (a moon of Neptune). ...

Read more here: » Celestial body atmosphere: Encyclopedia - Celestial body atmosphere

Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly 78% nitrogen and 21% oxygen, with trace amounts of other gases. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night. The atmosphere has no abrupt cut-off. It slowly becomes thinner and fades away into space. There is no definite boundary between the atmosphere and outer space. Three-quarters of the atmosphere's mass is with ...

Including:

Earth's atmosphere - Temperature and the atmospheric layers
Earth's atmosphere - Various atmospheric regions
Earth's atmosphere - Pressure Earth's atmosphere - Thickness of the atmosphere Earth's atmosphere - Composition
Earth's atmosphere - Heterosphere
Earth's atmosphere - Density and mass Earth's atmosphere - The evolution of the Earth's atmosphere

Read more here: » Earth's atmosphere: Encyclopedia - Earth's atmosphere

In the physical sciences, weight is the downward force exerted on matter as a result of gravity, especially the earth's gravity. An object's weight is equal to its mass multiplied by the magnitude of the gravitational field. The word entered Old English sometime around the 9th century, and meant the quantity measured with a balance. The word "weight" is commonly used synonymously with "mass", though the two concepts are technically quite distinct. Weight - Weight and mass. In scientific usage weight ...

Including:

Weight - Weight and mass
Weight - Units of weight and mass Weight - Converting between weight and mass in SI units
Weight - Sensation of weight Weight - Measuring weight Weight - Relative weights on the earth moon and planets Weight - Human weight in the medical sciences and ordinary language
Weight - Sports usage

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An object's weight, henceforth called "actual weight", is the downward force exerted upon it by the earth's gravity. By contrast, an object's apparent weight is the upward force (the normal force, or reaction force), typically transmitted through the ground, that opposes gravity and prevents a supported object from falling. It is apparent weight, rather than actual weight, that a spring weighing scale measures. Apparent weight is also responsi ...

Including:

Apparent weight - Objects at rest Apparent weight - Objects accelerating vertically
Apparent weight - Free-fall Apparent weight - Beyond free-fall
Apparent weight - Objects accelerating in arbitrary direction Apparent weight - Buoyancy Apparent weight - Other factors Apparent weight - External references

Read more here: » Apparent weight: Encyclopedia - Apparent weight

Since the Earth is in fact flattened slightly at the poles and bulges somewhat at the equator, the geometrical figure used in geodesy to most nearly approximate the shape of the Earth is an ellipsoid of revolution. The ellipsoid of revolution is the figure which would be obtained by rotating an ellipse about its shorter axis. An ellipsoid of revolution describing the figure of the Earth is called a reference ellipsoid. An ellipsoid of revolution is uniquely defined by specifying two dimensions. Geodesists, by convention, use the semim ...

See also:

Figure of the Earth, Figure of the Earth - Ellipsoid of revolution, Figure of the Earth - Historical Earth ellipsoids, Figure of the Earth - More complicated figures, Figure of the Earth - Geoid, Figure of the Earth - Correlations to Geophysics and Geology, Figure of the Earth - Earth rotation and Earth's interior, Figure of the Earth - Global and regional gravity field, Figure of the Earth - Literature

Read more here: » Figure of the Earth: Encyclopedia II - Figure of the Earth - Ellipsoid of revolution

It was stated earlier that measurements are made on the apparent or topographic surface of the Earth and it has just been explained that computations are performed on an ellipsoid. One other surface is involved in geodetic measurement: the geoid. In geodetic surveying, the computation of the geodetic coordinates of points is commonly performed on a reference ellipsoid closely approximating the size and shape of the Earth in the area of the survey. The actual measurements made on the surface of the Earth with certain instruments are however r ...

See also:

Figure of the Earth, Figure of the Earth - Ellipsoid of revolution, Figure of the Earth - Historical Earth ellipsoids, Figure of the Earth - More complicated figures, Figure of the Earth - Geoid, Figure of the Earth - Correlations to Geophysics and Geology, Figure of the Earth - Earth rotation and Earth's interior, Figure of the Earth - Global and regional gravity field, Figure of the Earth - Literature

Read more here: » Figure of the Earth: Encyclopedia II - Figure of the Earth - Geoid

Figure of the Earth - Earth rotation and Earth's interior. Dertermining the exact figure of the Earth is not only a geodetic operation or a task of geometry, but is also related to geophysics. Without any idea of the Earth's interior, we can state a "constant density" of 5.5 g/cm³ and, according to theoretical arguments (see Leonhard Euler, A. Wangerin, etc.), such a body rotating like the Earth would have an obliquity of 1:230. In fact the measured flattening is 1:298.25, which is more similar to a spher ...

See also:

Figure of the Earth, Figure of the Earth - Ellipsoid of revolution, Figure of the Earth - Historical Earth ellipsoids, Figure of the Earth - More complicated figures, Figure of the Earth - Geoid, Figure of the Earth - Correlations to Geophysics and Geology, Figure of the Earth - Earth rotation and Earth's interior, Figure of the Earth - Global and regional gravity field, Figure of the Earth - Literature

Read more here: » Figure of the Earth: Encyclopedia II - Figure of the Earth - Correlations to Geophysics and Geology

The possibility that the Earth's equator is an ellipse rather than a circle and therefore that the ellipsoid is triaxial has been a matter of scientific controversy for many years. Modern technological developments have furnished new and rapid methods for data collection and since the launching of the first Russian Sputnik, orbital data has been used to investigate the theory of ellipticity. A second theory, more complicated than triaxiality, proposed that observed long periodic orbital variations of the first Earth satellites indicat ...

See also:

Figure of the Earth, Figure of the Earth - Ellipsoid of revolution, Figure of the Earth - Historical Earth ellipsoids, Figure of the Earth - More complicated figures, Figure of the Earth - Geoid, Figure of the Earth - Correlations to Geophysics and Geology, Figure of the Earth - Earth rotation and Earth's interior, Figure of the Earth - Global and regional gravity field, Figure of the Earth - Literature

Read more here: » Figure of the Earth: Encyclopedia II - Figure of the Earth - More complicated figures

The 19 reference ellipsoid models listed below have had utility in geodetic work and many are still in use. The older ellipsoids are named for the individual who derived them and the year of development is given. In 1887 the English mathematician Col Alexander Ross Clarke CB FRS RE was awarded the Gold Medal of the Royal Society for his work in determining the figure of the Earth. The international ellipsoid was developed by John Fillmore Hayford in 1910 and adopted by the International Union of Geodesy and Geo ...

See also:

Figure of the Earth, Figure of the Earth - Ellipsoid of revolution, Figure of the Earth - Historical Earth ellipsoids, Figure of the Earth - More complicated figures, Figure of the Earth - Geoid, Figure of the Earth - Correlations to Geophysics and Geology, Figure of the Earth - Earth rotation and Earth's interior, Figure of the Earth - Global and regional gravity field, Figure of the Earth - Literature

Read more here: » Figure of the Earth: Encyclopedia II - Figure of the Earth - Historical Earth ellipsoids