[填空题]
Suppose a star the si0a5l 9rk*obu mz-.5yed;rv1(ea r6 udd *xtpese of our Sun, but with mass 8.0 times as great, were rotating at a speed of 1.0 revolution every 12 day;y6da-(.de1*tu re5sr expvds. 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 angular momentum. $\times10^{9 }$ $rev/day$
