The planet Mars has a satellite, Phobos, which travels in an orbit of radius 9.4 xm with a period of 7 hr 39 min. Calculate the mass of Mars from this information.

Scientists want to place a 4 × 103 kg satellite in orbit around Mars. They plan to have the satellite orbit a distance equal to 2.4 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 kgrmars = 3.397 x 106 mG = 6.67428 x 10-11 N-m2/kg2 1.)What is the force of attraction between Mars and the satellite? 2.)What speed should the satellite have to be in a perfectly circular orbit? 3.)How much time does it take the satellite to complete one revolution?

What is the escape speed from a planet of mass M = 3.1 x 1023 kg and radius R = 2.6 x 106 m? Write the answer in terms of km/s.

An asteroid has a mass of 3.66 × 10kg and a radius of 8.2 × 10m. If a 25 kg mass is dropped from 10 m above the “ground” of the asteroid, how long will it take the mass to fall to the ground?