Physics, asked by devanshirathi, 1 year ago

what is universal law of gravitation

Answers

Answered by Anonymous
3
Hi

Here is your answer,

Every body in this universe attracts each other with a force whose magnitude is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres. This force acts along the line joining the centres of two bodies.

Now, consider two bodies of masses m₁ and m with their centres mutually separated by a distance r. So, the force( in magnitude) of gravitational attraction between two bodies.

 According to Newton's Law of Motion:-

           F 
α mm ----------------> (1)

  and              F 
α 1/r² ---------------> (2)

From equation (1) and (2)

        F 
α mm/r²

 Gravitational force, F = G m
m/r² ------------------->(3)

where G is constant of proportionality known as gravitational constant. It is also known as universal gravitational constant.

In CGS system, the value of G is 6.67
×10⁻⁸ dyne cm² g⁻² and its SI value is 6.67×10 Nm² kg⁻²

DIMENSIONAL FORMULA FOR G

       G= F r²/mm = [ MLT⁻² ] [ L² ]/[M²]

       
= [ MLT⁻² ] [L³ [ [ M⁻² ] 

       = [ M
⁻¹ L ³T⁻² ]

Now suppose, m = m = 1 unit and r = 1 unit, then from Eq (3) 

      F = G 
××1/(1)² = F = G

Thus, universal gravitational constant (G) is numerically equal to the force of attraction acting between two bodies each of unit mass by unit distance apart.



Hope it helps you !
Answered by BrainlyQueen01
2
Universal Law of Gravitation ;

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The gravitational force of attraction between any two particles is directly proportional to the product of the masses of the particles and is inversely proportional to the square of distance between the particles. The direction of the force is along the line joining the two particles.

F ∝ m_1m_2 \: \: .......(1)

And,

F ∝ \frac{1}{r {}^{2} } \: \: .......(2)

Now , adding ( 1 ) and ( 2 ), we get ;

F ∝ \frac{m_1m_2}{r {}^{2} }

Or ,

F = G \frac{m_1m_2}{r {}^{2} }

Here, G is a constant known as the universal constant of Gravitation. The value of G was experimentally measured in the laboratory by Cavendish, long after Newton's death. This value is

G = 6.67 × 10 ^ - 11 Nm² / kg².

_______________________

Thanks for the question !
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