If the law of gravitation, instead of being inverse-square law, becomes an inverse-cube-law
a) planets will not have elliptic orbits
b) circular orbits of planets is not possible
c) projectile motion of a stone thrown by hand on the surface of the earth will be approximately parabolic
d) there will be no gravitational force inside a spherical shell of uniform density
If the law of gravitation, instead of being inverse-square law, becomes an inverse-cube-law
a) planets will not have elliptic orbits
b) circular orbits of planets is not possible
c) projectile motion of a stone thrown by hand on the surface of the earth will be approximately parabolic
d) there will be no gravitational force inside a spherical shell of uniform density

The correct options are

a) planets will not have elliptic orbits

c) projectile motion of a stone thrown by hand on the surface of the earth will be approximately parabolic

Explanation:

The planets will have a path of form if the law of gravitation becomes an inverce square law:  where a, K are constants. As a result, the stone thrown by hand on earth will have a roughly parabolic projectile motion.