Question

A helicopter has two blades (see figure), each of which has a mass of 220 kg and can be approximated as a thin rod of length 6.7 m. The blades are rotating at an angular speed of 45 rad/s. (a) What is the total moment of inertia of the two blades about the axis of rotation? (a) Determine the rotational kinetic energy of the spinning blades.

Answer 1

total moment inertia = 2* single rod I

http://en.wikipedia.org/wiki/List_of_moments_of_inertia