Need some help with Astronomy. I need to figure out the acceleration of gravity on the surface of certain planets. For example, I need to find the acceleration of gravity on Mars when the mass is .11 times the mass of Earth and the radius is .53 times the radius of Earth. Thanks in advance.
The acceleration of gravity at the surface of a planet (or any spherical object) with mass M and radius R is proportional to M/R^2. To compare it to the Earth's value of g, multiply by (M/Mearth)/(R/Rearth)^2
For Mars, that ratio is (0.11)/0.53)^2 = 0.39