[填空题]
A helicopter rotor b-juin1vmn3zbc8 i *h/u 7lu+fg h3z0oladerg - .i10 *w*n0aolvgygsv9fx can be considered a long thin rod, as shown in Fig. 8–4gr yvn.x v1s* ggiwa -09f0o*l6. (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? $m \cdot N$