physics
posted by Sam .
A 17.0kg satellite has a circular orbit with a period of 2.31 h and a radius of 9.10×106 m around a planet of unknown mass. If the magnitude of the gravitational acceleration on the surface of the planet is 8.10 m/s2, what is the radius of the planet?
radius = m

figure the centripetal acceleration v^2/r
where v=2PIr/T you are given r as 9.10E6
now set that acceleration equal to
8.10*(rp/9.1E6)^2 and solve for the radius of the planet rp. 
What is Plr?

Which values are solutions to the inequality below? Check all that apply. sqrtx