The acceleration due to gravity on the earth's surface is $g$. If the diameter of the earth reduces

Question

The acceleration due to gravity on the earth's surface is $g$. If the diameter of the earth reduces to half of its original value and mass remains constant, then acceleration due to gravity on the surface of earth would be

Professor PC Thomas Classes · Answer

$g = GM/R^2$. If $R \rightarrow R/2$, $g \rightarrow 4g$.