Spring loaded

I noticed an abandoned retractable ballpoint pen resting dismantled along the baseboard molding. Its internal coiled steel spring had rolled two inches free. Moving into a low crouch, I picked up the miniature coil between my thumb and forefinger to gauge its compressive resistance. It yielded under steady pinch force, storing potential energy cleanly along its axis. I positioned one end against the vertical wooden molding and braced the opposite tip with the flat edge of a discarded plastic bread tag. Applying forward mass through my wrist joint, I compressed the spring down to five millimeters. When I slipped my finger sideways to release the catch, the bread tag snapped forward across the parquet in a sharp, instantaneous trajectory, halting neatly four inches away.