Angular acceleration of a cylinder - four forces A uniform 4.4 kg cylinder (moment of inertia I = 1 2 mR2 ) can rotate about an axis through its center at O. The forces applied are : F1 = 6.1 N, F2 = 5.4 N, F3 = 2.8 N, and F4 = 5.9 N. Also, R1 = 13 cm and R3 = 6.2 cm. 5 Find the magnitude (in rad/s2) and direction (+ denotes counterclockwise and - denotes clockwise) of the angular acceleration of the cylinder.