The weight of the body at earth's surface is W. At a depth half way to the centre of earth its weight will be (Density of earth is uniform) :

Options

A. W
B. `(W)/(2)`
C. `(W)/(4)`
D. `(W)/(8)`

Answer

B

Explanation

`mg.=mg(1-(d)/(R ))`
`therefore W.=W(1-((R )/(2))/(R ))=(W)/(2)`
Hence correct choice is (b).