A tunnel is dug along the diameter of the earth. The gravitational force on particle of mass m placed in the tunnel at a distance .x. from the centre.

A tunnel is dug along the diameter of the earth. The gravitational for

1.	A tunnel is dug along the diameter of the earth. The gravitational force on particle of mass m placed in the tunnel at a distance .x. from the centre.
Answer» SOLUTION :Mass of earth `M=4/3 piR^3 rho` Mass of imaginarysphere, having radius x, `M_1=4/3 PI x^3 rho` (or)`M^1/M=x^3/R^3` `THEREFORE` Gravitational force on .m. due to `M_1` `F=(GM^1m)/x^2` (or) `F=(Gm)/x^2 (x^3/R^3 M)="GMmx"/R^3`