What is the source of centripetal force that a planet requires to revolve around the Sun? On what factors does that force depend?
The centripetal force required by a planet to remain in the orbit around the sun is provided by the gravitational force of attraction between the planet and the sun.
The centripetal force (F) depends on the radius (r) of the planets orbit, mass (m) of the planet and orbital speed (v) of the planet.
F = mv2/r