Question

State two applications of universal law of gravitation. What happens to the gravitational force between two objects when the distance between them is:
(i) Doubled?
​(ii) Halved?

Answer 1

Applications of Universal law of gravitation:

(i) The universal law of gravitation is used to calculate the value of acceleration due to gravity on planets.
(ii) It is also used to study the motion of the satellites around the planets, mainly earth.

The gravitational force of attraction between two bodies of mass 'm₁' and 'm₂' separated by a distance of 'r' = $\mathrm{G}\frac{m_1{m}_2}{r^2}$

So, the gravitational force $\propto \frac{1}{r^2}$

(i) As the gravitational force is indirectly proportional to the distance of separation, so if the distance between the objects is doubled, then the force of gravitation becomes one-fourth of the original value.

(ii) If the distance is halved, then the force of gravitation becomes 4-times the original value.