Question

Scientists want to place a 3100 kg satellite in orbit around Mars. They plan to have the satellite orbit a distance equal to 1.9 times the radius of Mars above the surface of the planet. Here is some information that will help solve this problem:
mmars = 6.4191 x 1023 kg
rmars = 3.397 x 106 m
G = 6.67428 x 10-11 N-m2/kg2
1)What should the radius of the orbit be (measured from the center of Mars), if we want the satellite to take 8 times longer to complete one full revolution of its orbit?
so far I have found speed to orbit 2085m/s and 8.2hrs to complete one revolution

Answer 1

object is 2.9 times radius from center. Remember to add Mars radius to altitude. I do not think you need the mass of the object.
F/m = a = = v^2/R = G Mmars / R^2 = omega^2 R