[填空题]
A potter is shaping a bowl on a potter’s wheel rotating at constant anguj0zdw: zd t98elewibh:,v h 9(lkk9 ro1ar speed (Fig. 8–42). The friction force between h9r1k: vhkhwe o9 (ib,ler hands and the clay is 1.5 N total. (a) How large is her torque on the wheel, if the diameter of the bowl is 12 cm? $m \cdot N$ (b) How long would it take for the potter’s wheel to stop if the only torque acting on it is due to the potter’s hand? The initial angular velocity of the wheel is 1.6 rev/s, and the moment of inertia of the wheel and the bowl is 0.11 $kg \cdot m^2$. s