Difference between revisions of "gravity"

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'''gravity''' is the tendency of objects with mass to accelerate toward each other.
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'''Gravity''' is the tendency of objects with mass to accelerate toward each other.
  
 
'''Newton's law of universal gravitation''' states the following:
 
'''Newton's law of universal gravitation''' states the following:
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     Every point mass attracts every other point mass by a force directed along the line connecting the two. This force is proportional to the product of the masses and inversely proportional to the square of the distance between them:
 
     Every point mass attracts every other point mass by a force directed along the line connecting the two. This force is proportional to the product of the masses and inversely proportional to the square of the distance between them:
  
     F = G \frac{m_1 m_2}{r^2}
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     ''F'' = - ''G'' ''M'' ''m'' / '''r'''<sup>2</sup>
  
 
where:
 
where:
  
     F is the magnitude of the (repulsive) gravitational force between the two point masses
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     ''F'' is the magnitude of the gravitational force between the two point masses
     G is the gravitational constant
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     ''G'' is the gravitational constant
     m1 is the mass of the first point mass
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     ''M'' is the mass of the first point mass
     m2 is the mass of the second point mass
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     ''m'' is the mass of the second point mass
     r is the distance between the two point masses
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     '''r''' is the distance between the two point masses
  
Assuming SI units, F is measured in newtons (N), m1 and m2 in kilograms (kg), r in metres (m), and the constant G is approximately equal to 6.67 × 10−11 N m2 kg−2 (newtons times metres squared per kilogram squared).
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Assuming SI units, ''F'' is measured in Newtons (N), ''M'' and ''m'' in kilograms (kg), '''r''' in metres (m), and Newton's gravitational constant ''G'' is approximately equal to 6.67 × 10−11 N m2 kg−2 (Newtons times metres-squared per kilogram-squared).
  
It can be seen that the repulsive force F is always negative, which means that the net attractive force is positive. (This sign convention is adopted in order to be consistent with Coulomb's Law, where a positive force means repulsion between two charges.)
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It can be seen that the force ''F'' is always negative. This sign convention is consistent with its electromagnetic equivalent ''Coulomb's Law'', where a positive force means repulsion between two charges.
  
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[[Category: Articles]]
 
[[Category:Glossary]]
 
[[Category:Glossary]]
{{Stub}}
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{{Mech-Stub}}

Latest revision as of 11:19, 14 October 2022

Gravity is the tendency of objects with mass to accelerate toward each other.

Newton's law of universal gravitation states the following:

   Every point mass attracts every other point mass by a force directed along the line connecting the two. This force is proportional to the product of the masses and inversely proportional to the square of the distance between them:
   F = - G M m / r2

where:

   F is the magnitude of the gravitational force between the two point masses
   G is the gravitational constant
   M is the mass of the first point mass
   m is the mass of the second point mass
   r is the distance between the two point masses

Assuming SI units, F is measured in Newtons (N), M and m in kilograms (kg), r in metres (m), and Newton's gravitational constant G is approximately equal to 6.67 × 10−11 N m2 kg−2 (Newtons times metres-squared per kilogram-squared).

It can be seen that the force F is always negative. This sign convention is consistent with its electromagnetic equivalent Coulomb's Law, where a positive force means repulsion between two charges.

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