Question

What is the source of centripetal force for:
(i) Motion of a planet around the Sun
(ii) A stone rotated in a circle by a string

Answer 1

Answer:

i)  Gravitational force (attractive) between sun and planet.

ii)

Answer 2

A force that pulls an object towards the centre of a circle is called centripetal force. The source for the centripetal force in the solar system is the gravitational force of the sun. Without the centripetal force from the sun the planets would travel in a straight line.