[填空题]
A centrifuge rotor rotating at 10,300 rpb wa04eacg6vajy+2 2 w 2t 5vfe;vpjuy5fpi,9m is shut off and is eventually brought uniformly to ,fpeiyvvu2p95 jt; 5frest 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