If acceleration due to gravity on Earth is g, then on a planet having the same mass as Earth but diameter one-third of Earth's diameter, g′=ng. The value of n is:

Question

G1 Physics · Accepted Answer

g=GM/R². The planet has the same mass but radius R′=R/3. Hence g′=GM/(R/3)²=9GM/R²=9g. Therefore n=9.