Newton's Law of Universal Gravitation

Q. State and explain Newton's Law of Universal Gravitation:-

Introduction:

In 1687, Sir Isaac Newton stated the Law of Universal Gravitation between two bodies.

Statement:

It states that, Any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of distance between them.

Explanation:

Law of Gravitation or Universal Gravitation says that in the whole universe there is always a force of attraction between bodies that allows them to attract each other, this force of attraction increases with the increase in mass and decreases with the decrease in distance between two bodies. This law is generally applies on heavenly bodies such as stars, moons, planets but it also apply on humans, animals and all other creatures however, due to the small mass as compared to heavenly bodies the force of attraction between creatures or humans is negligible.

Gravitational Force between two masses.

Mathematically we get:

F ∝ m1 × m2
F ∝ 1 ÷ r2

Now Combine both equations:

F ∝ m1 × m2 ÷ r2

Therefore:

F = G × m1 m2 ÷ r2

:. G is Newton's constant & value of G = 6.67 × 10-11 Nm2 /kg2