Answer to Question #21907 in Mechanics | Relativity for Lizbeth
Mars has a Mass of about 6.4*10^23kg, & it's moon Phobos has a mass of about 9.6*10^15kg. If the magnitude of the gravitational force between the two bodies is 4.6*10^15N, at what speed does Phobos orbit Mars?
let us find distance between Mars and Phobos
we know that F=G*m1*m2/r^2 then r = sqrt(G*m1*m2/F) = 9 438 643 m = 9438.6 km now we can find speed. v^2/r=a where a is centrifugal acceleration. a=F/m2 where m2 is mass of Phobos. Hence the speed is v=sqrt(r*a) = sqrt(r*F/m2 ) = 2 126.66 m/s = 2.1 km/s