The acceleration due to gravity at the surface of Earth is g.The radius of Earth is R_E.The distance from the center of Earth to a point where the acceleration due to gravity is g/9 is A)R_E B)9R_E C)R_E/3 D)3R_E E)None of these is correct.

Question

Quizplus · Accepted Answer

The acceleration due to gravity at a distance $r$ from the center of a planet of radius $R$ and mass $M$ is given by $g' = \frac{G M}{r^2}$, where $G$ is the gravitational constant. At the surface of the Earth, this acceleration is $g = \frac{G M}{R^2}$. To find the distance $r$ where the acceleration due to gravity is $g/9$, we set $g' = g/9$ and solve for $r$, leading to $r = 3R$, where $R$ is the radius of the Earth.

The Acceleration Due to Gravity at the Surface of Earth