The acceleration due to gravity at a height I km above the earth is the same as at a depth d below the , surface of earth. Then :

Question

$\begin{array}{1 1} (1)d= \frac{1}{2} km \\ (2) d= 1\; km \\ (3)d= \frac{3}{2} km \\ (4) d= 2 km \end{array}$