The loud crack of a deftly flicked bullwhip can certainly command attention. That distinctive noise is a small sonic boom, generated when the whip’s thin, highly flexible tip exceeds the speed of sound.
Swinging a leather bullwhip’s thick, rigid handle in an arc gives the whip angular momentum. Sharply reversing the motion’s direction sends a wave down the whip. As the wave travels toward the tip along a tapering path, it moves more and more rapidly–a consequence of the conservation of angular momentum. In the end, the narrow tip’s supersonic motion through the air produces a shock wave.