[填空题]
A helicopter rotor blade c1wgd1 1g9;fvz ewr t(h:xx+ ddan be considered a long yyzjhwags rox o w-43 r.*2-u6thin rod, as shown in Fig. 8–46.axrs uo 2rw -h4wy.6g3*yz j-o (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? $m \cdot N$