If g is acceleration due to gravity on the surface of the earth ,having radius R , the height at which the acceleration due to gravity reduces tog2 is
R/2
2R
2-1R
gh=gRR+h2 ⇒g2=gRR+h2 ∵ gh=g2 ⇒12=RR+h2 ⇒12=RR+h ⇒R+h=2R ⇒h=2-1R