Earth is a sphere of uniform mass density. If the weight of the body is `10 n N` half way down. The body weighed `100 N` on the surface. An infinite collection of equal masses of `2kg` each are kept on a horizontal line (`X`-axis) at positions `x=1m,2m,4m,8m`...... find the gravitational potential at `x=0` in `GJ` unit.

Answer

5

Explanation

`mg'=mg(1-d/R)` where `d` is the depth `=mg(1-1/2)=(mg)/2=50 N`