A helicopter rotor blade can be considered a long thin rod, as shown in the figure above.
Each of the three rotor blades is L = 3.87 m long and has mass m = 151 kg.
What is the moment of inertia of the rotor about its axis of rotation?
How much torque must the motor apply to bring the blades up to a speed of 4.69 revolutions per second in 8.76 s?