Two blocks are connected by a light string passing over an ideal pulley. The block with mass m1 = 20.0 kg slides on a frictionless horizontal surface, while the block with mass m2 = 1.00 kg hangs vertically. The radius of the pulley is 6.00 cm. Assuming that the pulley rotates such that the string doesn’t slip, find the magnitude of the angular acceleration of the pulley. Enter a positive answer if the direction of angular acceleration is anticlockwise in the picture and a negative answer if the direction of angular acceleration is clockwise in the picture.