Question

Compute g at a distance of 6. 8 x 10⁷m from the center of a spherical object whose mass is 5.0 x 10²³kg.

Answer 1

Gravitational acceleration, created by the object of mass $M$ at the distance $r$ from the center of it is $g = G \frac{M}{r^2}$, where $G = 6.67 \cdot 10^{-11} m^3 kg^{-1} s^{-2}$ is gravitational constant.

Hence, $g = \frac{ 6.67 \cdot 10^{-11} m^3 kg^{-1} s^{-2} \cdot 5 \cdot 10^{23} kg }{(6.8 \cdot 10^7 m)^2} \approx 0.0072 \frac{m}{s^2}$.