[填空题]
The rings of Saturn are composed ogb 69ppohw99v: b2eubf chunks of ice that orbit the plakg8pgv2 y+ n,esbd *q(net. The inner radius of the rings is d2p(bks ,*+evgyq gn8 73,000 $\mathrm{~km}$ , while the outer radius is 170,000$ \mathrm{~km}$ . Find the period of an orbiting chunk of ice at the inner radius and the period of a chunk at the outer radius. Compare your numbers with Saturn's mean rotation period of 10 hours and 39 minutes. The mass of Saturn is 5.7 $\times 10^{26} \mathrm{~kg}$ .
