[填空题]
A centrifuge rotor rotajm sk, mc7kg54ting at 10,qn * )/2) kih qb, m:ebbyi5xh.gel2va300 rpm is shut off and is eventually brought k/ e bi,egqb )x)25h hy.m:ivbl qa*2nuniformly 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