Total length of two blades L = 6.7 m + 6.7 m
                                      Â
= 13.4 m
Total Mass of the blades M = 220 + 220 = 440 kg
Angular speed w = 43 rad / s
(a) the total moment of inertia of the two
blades about the axis of rotation
             Â
I = ML 2 / 12
              Â
= 6583.86 kg m 2
(a) the rotational kinetic energy of the
spinning blades K = ( 1/ 2) I w 2
                                                                               Â
= 6.086 x 10 6 J