A barbell consists of a uniform rod with a mass attached to each end. The rod is 2.2 m long and has a moment of inertia about its center of mass of 1.5 kg.m^2. The center of each 3.0-kg mass is attached to the end of the rod. Calculate the rotational momentum of the barbell when it rotates at 0.50 rad/s about the center of the rod.