🌀 The tip of a whip, when cracked, breaks the sound barrier - the characteristic crack is a mini-sonic boom.
It works by conserving momentum: energy is transferred from the thick handle to the thin tip, and the smaller the mass, the higher the speed. As a result, the tip accelerates to 1200-1500 km/h, which is Mach 1+.
This was experimentally confirmed only in 1927 with high-speed photography. In 2002, Goriely and McMillen showed that at the moment of the crack, the tip moves almost twice as fast as sound.