[填空题]
A centrifuge rotor rotating at 10,300 ht ;.8/.zplqp9i,fki y2mpc m rpmi*l;x;k7 ul nz is shut off and is eventually brought uniformly to rest by a frictional torque o;l* xznk;l u7if 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