Physics

Problem

A light planet is revolving around a massive star in a circular orbit of radius

R

with a period of revolution

T

. If the force of attraction between planet and star is proportional to

R^{-3/2}

then choose the correct option : (1)

T^2 \propto R^{5/2}

(2)

T^2 \propto R^{7/2}

(3)

T^2 \propto R^{3/2}

(4)

T^2 \propto R^3