Solution Found!
A helicopter rotor blade can be considered a long thin rod, as shown in Fig. 8–46. (a)
Chapter 8, Problem 40P(choose chapter or problem)
(II) A helicopter rotor blade can be considered a long thin rod, as shown in Fig. 8-46. (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. (b) How much torque must the motor apply to bring the blades up to a speed of 5.0 rev/s in 8.0 s?
Figure 8-46
Questions & Answers
QUESTION:
(II) A helicopter rotor blade can be considered a long thin rod, as shown in Fig. 8-46. (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. (b) How much torque must the motor apply to bring the blades up to a speed of 5.0 rev/s in 8.0 s?
Figure 8-46
ANSWER:Solution
Step 1 of 2
- We need to find out the moment of inertia of the three rotor blades of the helicopter about the axis of rotation.
There are three blades so the moment of inertia is given by,
The length of the rotor helicopter blade is,
The mass of the rotor helicopter blade is,
So,
The moment of inertia of the three rotor blades of the helicopter about the axis of rotation is .