[填空题]
A centrifuge rotor rotating at 10,300 rpm is shut off auzj/4 :wqvd8 ynd is eventually brougrd/vydi af37 .ht uniformly to rfyi a3v.dd/r 7est by a frictional torque of 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