Two satellites S1 and S2 revolve around a planet in coplanar circular orbits in the same sense. Their periods of revolution are 1 h and 8 h respectively. The radius of the orbit of S1 is 104 km. When S2 is closest to S1, then the speed of S2 relative to S1 will be
Aπ × 104 km h-1
B2π × 104 km h-1
C1 × 104 km h-1
D2 × 104 km h-1
could anyone give me a detailed solution for this?