Question

At what height above the earth's surface the acceleration due to gravity will be 1/9th of its value at the earth's surface? Radius of earth is 6400km

Answer 1

GIVEN:
g'=g/9

formula used 

g'=(1+2h/Re)

Calculation

g/9=g(1+2h/Re)

1/9 = (1-2h/Re)

1/9-1=-2h/Re

1-9/9=-2h/Re

1-9=-18h/Re

-8=-18h/Re

4=9h/Re

4Re=9h

4Re/9=h

h=4Re/9

h=(4 ×6400 )9

Answer :h=2844.4445km