[填空题]
A helicopter rotor bladiyal q9;z,vd 8e ca m i6f)p*m,bevtd13 w6f/2qji 2i cckrn be considered a long thin rod, as shown in Fig. 8–46.jtiv*mdrb/e w23pim6i cqfc162 ,k ) f (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? $m \cdot N$