In the figure here, a cylinder having a mass of 1.1 kg can rotate about its central axis through point O. Forces are applied as shown: F1 = 6.5 N, F2 = 6.5 N, F3 = 2.6 N, and F4 = 2.1 N. Also, r = 2.2 cm and R = 11 cm. Taking the clockwise direction to be negative, find the angular acceleration of the cylinder. (During the rotation, the forces maintain their same angles relative to the cylinder.)