1. Decreases.
The value of acceleration due to gravity at a height ‘h’ above the ground ‘gh’ is given by, gh =g[1-2h/Re] where Re is radius of Earth. Therefore gh decreases with an increase in height.
2. Decreases.
The value of acceleration due to gravity at a depth ‘d’ below the ground (gd), is given by, gd =gh =g[1-2h/Re] where Re is the radius of earth. This shows that with an increase in the value of ‘d’ i the value of gd decreases.
3. Mass of the body.
The acceleration due to gravity of any planet of mass ‘M’ and radius ‘R’ is given by, g = GM/R2, where, G is the universal gravitational constant. So, the value of ‘g’ is dependent on the mass of the earth but independent of mass of the body.
4. More accurate.
The gravitational potential energy of any point at a distance ‘r’ from the centre of the earth is V (r) = GmM/r
So, Potential Energy difference
= gm (r2 – r1)
= mgr2 – mgr1
(Assuming r2 – r1 ≈ R2 )
Thus -GmM (1/r2 -1/r2) is a more accurate relation.