[填空题]
The rings of Saturn are composed of d8 xt, bz9lvbcpd 1d,7 p-/qlgchunks otybn5* +p:p pjf ice that orbit the planet. The inner radius of the rings is 73,000 5 ptp:njy+b*p $\mathrm{~km}$ , 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 $\times 10^{26} \mathrm{~kg}$ .
