Question
Prove that the value of acceleration due to gravity at the surface of the earth is more than that at points above and below it.
Solution
The value of acceleration due to gravity varies with altitude, depth, shape and rotation of earth about it's axis.
i) On the surface of the earth,
g = 
... (1)
ii) At a height h above the surface of the earth,
g' = 
... (2)
iii) At a height below the surface of the earth,
g ' = 
... (3)
From (1), (2) and (3), we can say that the value of 'g' decreases with height and is maximum on the surface of the earth.
That is why, the value of 'g' is lesser at mountains than in plains.
