Question

The height of any point P above the surface of earth is equal to diameter of earth. The value of acceleration due to gravity at point P will be (Given g = acceleration due to gravity at the surface of earth).

• A. $\frac g2$
• B. $\frac g4$
• C. $\frac g3$
• D. $\frac g9$

Answer 1

Answer: (D)

$\frac g9$

Answer 2

We know that
$g' = \frac {GM}{(R+h)^2}$
Given $h = 2R$
$g' = \frac {GM}{(R+2R)^2}$

$g' = \frac {GM}{(3R)^2}$

$g' = \frac {GM}{9R^2}$

$g' = \frac {g}{9}$

so, the correct option is (D): $\frac g9$