1. A 5.0 megawatt windmill has three 45 m-long blades that can be approximately viewed as straight rods. If the rotational speed of the rods is 6 rpm, what is the mass of each rod? (Hint 1: the moment of inertia of the rod is I = (1/3) mr2, where m is the mass and r the length. Hint 2: Use the kinetic energy of rotational motion: K = ½ Iw2. Assuming 100% efficiency of energy conversion from kinetic to electrical).