[填空题]
A science-fiction tale describes an artificial 2vo/q +hju(m dj lov+;"planet" i: sj6 /a)lwmson u(4pun the form of a band completely encircling a sun (Fig. 5-40). The inhabitants live on the inside surface (where it is always noon). Imagine that this sun is exactly like our own, that the distance to the band is the same as the Earth-Sun distance (to make the climate temperate), and that the ring rotates quickly enough to produce an apparent gravity of g as on Earth. What will be the period of revolut ljm6s(/pauw:) nou4sion, this planet's year, in Earth days?
