A satellite that has a mass of 300 kg moves in a circular orbit 5.00×10^7 m above Earth’s surface. What is the gravitational force on the satellite? What is the speed of the satellite? What is the period of the satellite?

Use the law of gravity to find the gravitational force acting on the satellite. The application of Newton’s second law will lead us to the speed of the satellite and its period can be found from its definition.
http://physics.weber.edu/amiri/physics1010online/WSUonline12w/OnLineCourseMovies/CircularMotion&Gravity/reviewofgravity/ReviewofGravity.html