Question

what is G and relationship between G and g and derivation for G And g

Answer 1

GM=gr2
r is the distance between object and the center of earth r=h+R
h is height of object from the surface and R is the radius of earth.
and 
g=43πGRρ

Explanation:

Suppose Earth is a sphere of radius r. It has mass M.
Gravitational Force on the object of mass m which is situated at a distance r from the center of Earth is
F=GMmr2 . . .[A]

If the object is free falling from the height h from the surface of earth (or at a distance r from the center of earth) it experience the acceleration g

it may hopefull

Answer 2

GM=gr2

r is the distance between object and the center of earth r=h+R

h is height of object from the surface and R is the radius of earth.

and 

g=43πGRρ

Explanation:

Suppose Earth is a sphere of radius r. It has mass M.

Gravitational Force on the object of mass m which is situated at a distance r from the center of Earth is

F=GMmr2 . . .[A]

If the object is free falling from the height h from the surface of earth (or at a distance r from the center of earth) it experience the acceleration g

it may hopefull