Question

The height at which the acceleration due to gravity becomes g/9 (where, g is 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/√3

(c) R/2

(d) √2R

Answer 1

Correct Option (a)  2R

Explanation: 

As value of acceleration due to gravity above the earth surface is g

g'  = GM/(R + h)² acceleration due gravity at height h