The Pulley Experiment

I located a braided fabric cable resting loosely across the desk edge. One end draped toward the floor while the other curled near a heavy ceramic mug. I stepped forward and gripped the cord with both hands, bracing my feet against the textured rim of a notebook. Leaning my upper frame backward at thirty degrees, I pulled. The cord tightened. Friction against the smooth desk surface resisted the tension cleanly. When I released one grip, the cord relaxed by four millimeters. It functions reliably as a manual tether.