The earth has radius R.A satellite of mass 100 kg is in orbit at an altitude of 3R above the earth's surface.What is the force that Earth exerts on the satellite at the altitude of its orbit?
A)61 N
B)110 N
C)9000 N
D)16,000 N

Question

Quizplus · Accepted Answer

The gravitational force $F$ between the Earth and the satellite is given by $F = G \frac{Mm}{r^2}$, where $G$ is the gravitational constant, $M$ is the mass of the Earth, $m$ is the mass of the satellite, and $r$ is the distance from the center of the Earth to the satellite. At an altitude of $3R$, the distance $r = 4R$. Substituting the values and simplifying, we find that the force is closest to 61 N.

The Earth Has Radius R