What will be the value of acceleration due to gravity on the surface of the earth if the radius of t

Question

What will be the value of acceleration due to gravity on the surface of the earth if the radius of the earth saddenly decreases to $60 \%$ of its present value, keeping the mass of the earth unchanged?

Professor PC Thomas Classes · Answer

$g = GM/R^2$. If $R$ decreases to $60\%$, $g' = g / (0.6)^2 = 9.81 / 0.36 = 27.25 \mathrm{~m/s^2}$.