A uniform helicopter rotor blade is 7.40 meter long and has a mass of 110 kilogram, and is attached to the rotor axle by a single bolt.
(a) Find the magnitude of the force on the bolt from the axle when the rotor is turning at 320rev/min? (Hint: For this calculation the blade can be considered to be a point mass at its center of mass. Why?)
N
(b) Compute the torque that must be applied to the rotor to bring it to full speed from rest in 6.7 second. Neglect air resistance. (The blade cannot be considered to be a point mass for this calculation. Why not? Suppose the mass distribution of a uniform, thin rod.)
N•m
(c) Determine how much work does the torque do on the blade in order for the blade to reach a speed of 320 rev/min?
J