[填空题]
A centrifuge rotor rotating at 10,300 rpm is shut off and is eventu/ nmdusx0xxjua(; vb m :7-6baqg7a6v e hv1wse2x:*mally brought unif1he2 xmsw* ve:ormly to rest 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