The distances from the centre of the earth, where the weight of a body is zero and one-fourth that of the weight of the body on the surface of the earth are (assume `R` is the radius of the earth)

Options

A. `0,R/4`
B. `0,(3R)/4`
C. `R/4,0`
D. `(3R)/4,0`

Answer

A

Explanation

The weight of the bodyy at the centre of the earth is equal to zero because
`g_("centre")=g(1-d/R)=g(1-R/R)=0`
`(g_(1))/g=(1-d/R)=1/4impliesd=(3R)/4`
So from the centre `d'=R/4`