[填空题]
Suppose a star the s-z nrhy4/l 0nsu4yyr.pd b44x ize of our Sun, 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, an.4y4p 4xy dburd that the lost mass carries off no angular momentum. $\times10^{9 }$ $rev/day$