Question

The height at which the acceleration due to gravity becomes g/9 (where g = the acceleration due to gravity on the surface of the earth) in terms of R, the radius of the earth is

(a) 2R 

(b) R/√2

(c) R/2 

(d) √2R

Answer 1

(a) : The acceleration due to gravity at a height h from the ground is given as g/9.

therefore, r = 3R
The height above the ground is 2R.