[填空题]
A projected space station consists o)iez 5cj6j5xn : xi1mbf a -fscgfz y+s+i )3tv-at8 cio) circular tube that will rotate about its center (like a tubular bicycle tire) (Fig. 5–42). The circle forme-f g+v3a)cs-+)ii yo szft8ctd by the tube has a diameter of about 1.1 km. What must be the rotation speed (revolutions per day) if an effect equal to gravity at the surface of the Earth (1.0 g) is to be felt?$\approx$ $\times 10^3$
