A solid shere of mass m and radius r is placed inside a hollow spherical shell of mass `4m` and radius `4r` find gravitational field intensity at
(a) `r lt y lt 2r` (b) `2r lt y lt 8r` (c) `y gt 8r`
here coordinate is measured from the point of contact of the sphere and the shell
.

Answer

`((Gm(y-r))/(r^(3))(-hatj))`
(b) `((Gm)/((y-r)^(2))(-hatj))`
(c) `((4G)/((y+4r))^(2)+(Gm)/((y-r)^(2)))(-hatj)` .