Q: Let ω be the angular velocity of the earth’s rotation about its axis. The acceleration due to the gravity at the surface of earth near the poles is g. An object weighed at the equator gives the some reading as a reading taken at a depth d below earth’s surface at a pole (d << R). The value of d is

(a) $\frac{\omega^2 R^2}{g}$

(b) $\frac{\omega^2 R^2}{2g}$

(c) $\frac{2\omega^2 R^2}{g}$

(d) None of the above

Ans: (a)