The height at which the acceleration due to gravity becomes g/9

• Gravitation

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

1. (√2)R
2. R/2
3. R/√2
4. 2R

Answer

GM/(9R²) = GM/(R + h)²

3R = R + h

h = 2R

The correct option is D.