# Problem 9-56 Vector Gravitational Field - B

A spaceprobe is at the position shown in the figure. Use components to determine the gravitational acceleration (magnitude and direction) of the probe due to the effects of the earth and moon. The masses of the earth and moon are $6.0 \times10^{24}\; kg$ and $7.4 \times 10^{22} \; kg$, respectively.

Accumulated Solution

Correct.

While no orthogonal coordinate system is wrong, this is the most convenient for the problem.

The expression for the gravitational field of a mass $M$ at a distance $r$ is;

(A)   $g = GM/r$

(B)   $g = GMr$

(C)   $g = GM/r^2$