Asatellite with a mass of 290 kg moves in a circular orbit 3.00 107 m above the earth's surface. what is the speed of the satellite if the force on the satellite is 87.4 n?

 A satellite with a mass of 310 kg moves in a circular orbit 8.00 107 m above the Earth's surface. 

(a) What is the gravitational force on the satellite? 
Fg= [(6.67x 10^-11)(310)(5.98 x 10^24)] divided by 
(8.00107m)^2 
Fg= you solved it. Fg= mv^2/r, radius 6400 miles? 

(b) What is the speed of the satellite? in km/s 
v= sqrt (2gh) 
v= you solved it. 

(c) What is the period of the satellite? in h 
t= 2d/ g. 
t= you solve it.