A cylinder of inertia 1.28 kg·m^2 rotates about a vertical frictionless axle with angular velocity 28 radians/second. A second cylinder of inertia 2.2 kg·m^2 is initially not rotating and it drops onto the first cylinder. The two surfaces are rough and they eventually come to the same angular velocity. Calculate the magnitude of the loss of kinetic energy (in J). (Do not include units in your answer).