- #1
captainjack2000
- 99
- 0
Helicopter's main rotor consists of 4 4m long individual blades. One end of each of the four blades is attached to a central motor unit. Assuming that each of the blades has a uniform mass per unit length of 7.5 kg/m calculate the moment of inertia of the main rotor.
blades are set to rotate at 6000rotations/min. Calculate the total angular momentum of the main rotor.
moment of inertia of a rod about one end is (Ml^2)/3
so I did (7.5kg/m x 4m)(4^2)/3
= 160 what units?
4x160 since there are four blades? = 640
6000rotations/min Angular momentum given by L=Iw =640 x (6000/60) = 64000 which seems too big!
could someone tell me if this is right
thanks
blades are set to rotate at 6000rotations/min. Calculate the total angular momentum of the main rotor.
moment of inertia of a rod about one end is (Ml^2)/3
so I did (7.5kg/m x 4m)(4^2)/3
= 160 what units?
4x160 since there are four blades? = 640
6000rotations/min Angular momentum given by L=Iw =640 x (6000/60) = 64000 which seems too big!
could someone tell me if this is right
thanks