[填空题]
A helicopter rotor blade canbzrkh4:2 9z-f,,x.k o:asua xanjw.u be:yv 4 8 zoj817gc ncqwe3eq;:ypnt.l n considered a long thin rod, as shown in Fig. 8–46.onleyq 13 v;4n:7n jt8cy8c .pgqe:zw (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? $m \cdot N$