Question

The acceleration of a body due to the attraction of the earth (radius R) at a distance 2R from the surface of the earth is (g = acceleration due to gravity at the surface of the earth)

• A. $\frac{g}{9}$
• B. $\frac{g}{3}$
• C. $\frac{g}{4}$
• D. g

Answer 1

Answer: (A)

$\frac{g}{9}$

Answer 2

$\frac{\mathbf{g}^{\mathbf{'}}}{\mathbf{g}}\mathbf{=}\left( \frac{\mathbf{R}}{\mathbf{R + h}} \right)^{\mathbf{2}}\mathbf{=}\left( \frac{\mathbf{R}}{\mathbf{R + 2R}} \right)^{\mathbf{2}}\mathbf{=}\frac{\mathbf{1}}{\mathbf{9}}$

$\therefore$ $g^{'} = \frac{g}{9}$.