A block of mass m = 13,9 kg is attached to the free end of a light string wrapped around a reel of radius R = 0,38 m and mass M = 7,2 kg. The reel is a uniform disk and fixed on an axis about which it is free to rotate as shown in the figure below. Determine the angular acceleration (magnitude) of the pulley. Express your answer in units of rad/s using one decimal place. Take g = 9.80 m/s. Note: The moment of inertia of a uniform disk is Idisk = MR. Assume the rope is massless and it does not slip over the pulley. M m R