Q: The change in the value of g at a height h above the surface of earth is the same as at a depth d below the earth. When both d and h are much smaller than the radius of earth, then which one of the following is correct?
(a) d = h/2
(b) d = 3h/2
(c) d = 2h
(d) d = h
Ans: (c)
$ \displaystyle g_h = g_d $
$ \displaystyle g(1-\frac{2h}{R})= g(1-\frac{d}{R})$
d = 2h