The acceleration due to gravity on the surface of Mars is 3.7 m/s^2. What is the acceleration due to gravity at a distance of 1 mars radius above the surface of Mars?

Question

The acceleration due to gravity on the surface of Mars is 3.7 m/s^2. What is the acceleration due to gravity at a distance of 1 mars radius above the surface of Mars?

What equation should I use for this and why?

How do I even solve?!?!?

Answer 1

To solve this you need Newton's Law of Universal Gravitation

F=G m1m2/r^2

If you go one mars radius above the surface you are now a distance of 2r from the center. As gravitation follows an inverse square law, it is relatively easy to compare the accelerations at the surface and one radius above the surface with math you can do in your head which I will leave you to figure out.