[填空题]
A helicopter rotor blad6rxkl2lzem.wf :p: o+ e can be 3c7te c. da 05uaj *gdy ccoob070rtl9considered a long thin rod, as shown in Fig. 8–46.obudj007r7acc* 93d etlcay.t5 g0co (a) If each of the three rotor helicopter blades is 3.75 m long and has a mass of 160 kg, calculate the moment of inertia of the three rotor blades about the axis of rotation. $kg \cdot m^2$ (b) How much torque must the motor apply to bring the blades up to a speed of 5 $rev/s$ in 8.0 s? $m \cdot N$