A solid sphere of mass `m` and radius `r` is placed inside a hollow thin spherical shell of mass `M` and radius `R` as shown in the figure. A particle of mass `m'` is placed on the line joining the two centres at a distance `x` from the point of contact of the sphere and the shell. Find the magnitude of the resultant gravitational force on this particle due to the sphere and the shell if

`xgt2R`

Options

A. `(Gmm'(2r-x))/(2r^3)`
B. `(Gm m'(x-r))/(2r^3)`
C. `(Gm m'(x-r))/r^3`
D. `(Gm m'(2x-r))/r^3`

Answer

C

Explanation

`therefore F_"net"=(Gm m')/r^3(x-r)`