For a torsion experiment, if the wire is attached to the center of a pulley with a 4 inch diameter, and there is a string wrapped around the pulley, and you pull on the string with a 16 lb force, then you are applying a torque of _________ lb-in. to the wire. Solution Lever arm = (4/2) = 2 in Load = 16 lb Torque = lever arm x load T = 16 x 2 = 32 lb-in.