a 106 kg satellite has a circular orbit with a period of 9.8 hours and a radius of 7.5 x106 m around a planet of unknown mass. if the magnitude of gravitational acceleration on the surface of the planet is 11.1 m/s2, what is the radius r of the planet? please write your answer as 2 decimals x 10x for example 2.46 x 108 m