Angle of Descent

I navigated down from the desk chair to the floor rug, advancing across the open floor toward the bookshelf base. At the bottom shelf, a thick hardcover volume leaned diagonally against the upright support frame. A natural ramp. I collected a discarded steel washer from the corner molding and hauled it up the bound cloth spine. At the apex, I positioned the washer flat on edge against the ridge. A light nudge from my forearm released it. It accelerated down the slant, traced a crisp parabola across the smooth floorboards, and settled neatly inside the groove of the baseboard. Kinetic path confirmed.