Question

Question 1 How does the force of gravitation between two objects change when the distance between them is reduced to half?

Class 9 - Science - Gravitation Page 143

Answer 1

According to Universal Law of gravitation, the gravitational force of attraction between any two objects of masses M and m be

F = G×M×m / r²
And r be the distance between two masses

If the distance between them is halved, then new distance
r¹ = r/2

New force F¹ = G×M×m / (r¹)²
                 F¹ = G×M×m / (r/2)²
                 F¹ = 4 [G×M×m / r²]
                 F¹ = 4F

When the distance between the masses is reduced to half, the gravitational force increases by 4 times than the original one. 

Answer 2

Answer:

The force of gravitation between two objects is inversely proportional to the square of the distance between them therefore the gravity will become four times if distance between them is reduced to half.