P-1 Gravitation — Science STD 10 — Question

[Note : In the usual notation, the magnitude of the weight of a body on the earth s surface is W = $\frac{G m M}{R^{2}}$ = $m\frac{G M}{R^{2}}$ = mg. Thus, W ∝ g. Hence, weight varies just like the acceleration due to gravity. It is maximum at the poles and minimum at the equator. It decreases with altitude (ft) and depth (d) below the earth’s surface. It becomes zero at the earth ’s centre. At a height above the earth ’s surface, W = $\frac{G m M}{(R+h)^{2}}$ at a depth d below the earth ’s surface, W = $\frac{G m M(R-d)}{R^{3}}$. Weight has magnitude and direction (towards the earth ’s centre). It is a vector quantity.]