[填空题]
Suppose a star the sd wa0*d+*nctc v3k n8zize of our uq yc32zt3l19pu;smjSun, but with mass 8.0 times as great, were rotating at a speed of 1.0 revolution every 12 days. If it were to undergo gravitational collapse to a neutron star of radius 11 km, losing three-quarters of its mass in the process, what would its rotation speed be? Assume that the star is a uniform sphere at all times, and that the lost mass carries off no 2j1y qp t3mus39u;lczangular momentum. $\times10^{9 }$ $rev/day$