Gravitation

Newton's law of universal gravitation
Derivation of Newton's law of universal gravitation

          

Newton's law of gravitation, states that every particle of matter in the universe attracts every other particle in the universe with a force varying directly as the product of their masses and inversely as the square of the distance between the particles.

Let there are two objects of mass m₁ and m₂ and the distance between the objects is r, then according to law of universal attraction, the attraction between the objects
       F \( \alpha \,m_1 \,x\,\,m_2 \) Eq-1
          \( F\alpha \frac{1} {{r^2 }} \)  Eq-2
By combining Eq-1 and Eq-2 we get
      \( F\alpha \frac{{m_1 \,x\,\,m_2 }} {{r^2 }} \)
       \( F = G\frac{{m_1 \,x\,\,m_2 }} {{r^2 }} \)
Where G is constant which is called Universal Gravitational constant & the value is 6.67 × 10^-11.