A body weighs W newton at the surface of the earth. Its weight at a height equal to half the radius of the earth, will be

Options

A. `(W)/(2)`
B. `(2W)/(3)`
C. `(4W)/(9)`
D. `(W)/(4)`

Answer

c

Explanation

Weight on earth is given by
`W=Mg=(GmM)/(R^(2))" "(because g=(GM)/(R^(2)))`
`therefore" "(W')/(W)=((R)/(R+h))^(2)" here h"=(R)/(2)`