[填空题]
A centrifuge rotor rotatid 7/s/n r6 li b (dey,onou3h)q;to7okng at 10,300 rpm is shut off and is yogw 1/dx -/kueventually brought uniformly to rest by a frictional torque o/o/y -wux 1kdgf 1.2 $m \cdot N$ If the mass of the rotor is 4.80 kg and it can be approximated as a solid cylinder of radius 0.0710 m, through how many revolutions will the rotor turn before coming to rest, $rev$ how long will it take? s