[填空题]
A helicopter rotor bv7 g9ukg6 ag*wlade can be consid qqyxj 0r g hj92810jl0ur*jleered a long thin rod, as shown in Fig. 8–48 lr el1 qjq90yrjhg0ux0jj* 26. (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? $m \cdot N$