ثابت الجاذبية

http://ar.wikipedia.org/wiki/ثابت_الجاذبية

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Note added at 6 mins (2014-09-22 19:13:54 GMT)
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http://en.wikipedia.org/wiki/Gravitational_constant

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Note added at 6 mins (2014-09-22 19:14:22 GMT)
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http://www.translatorscafe.com/cafe/EN/units-converter/accel...

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Note added at 7 mins (2014-09-22 19:15:15 GMT)
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Excerpt:
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Acceleration and Gravity

Gravitational force is one of the major forces that acts on objects and affects their acceleration. For objects near the surface of the Earth, it pulls them towards the Earth. When no other forces act upon an object released above the ground, it is said to be in free fall. It falls with acceleration of 9.80665 meters per second squared. This value is denoted as a constant g, and can be used in calculating the weight of an object. Since F = ma according to the Second Newton’s Law, weight, which is the force acting upon the object, is the product of the object’s mass and g. The mass of the object can be calculated easily, thus the weight is also easy to find. It is important to remember that the common use of “weight” actually refers to mass.

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Note added at 14 mins (2014-09-22 19:22:04 GMT)
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