PhysicsMedium159×since 2002Q7137The mass density of a planet of radius R varies with the distance r from its centre as ρ\rhoρ(r) = ρ0(1−r2R2){\rho _0}\left( {1 - {{{r^2}} \over {{R^2}}}} \right)ρ0(1−R2r2). Then the gravitational field is maximum at :Ar=13Rr = {1 \over {\sqrt 3 }}Rr=31RBr = RCr=34Rr = \sqrt {{3 \over 4}} Rr=43RDr=59Rr = \sqrt {{5 \over 9}} Rr=95RCheck answerSkip