[填空题]
A centrifuge rotor rotat (qt( +ia7s(tttqb-p ning at 10,300 rpm is shut ofx jb++p3eqa :wf and is eventually brought uniformly to rest by a:wa+b x3+j eqp 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