Why whip crack

But if the tip were truly the cause of the crack, why wasn't the sound heard earlier, when the tip first reached the speed of sound? Goriely and McMillen's calculations have revealed the answer. He notes that even though some parts of the whip travel at greater speeds, "it is the loop itself that generates the sonic boom.

Although the whip's tip has lost the distinction of being the source of the menacing crack, it is still a force to be reckoned with: according to Goriely's calculations, "the tip can reach speeds more than 30 times the initial speed [of the whip]. Already a subscriber? Sign in. When the cracker moves faster than speed of sound, it creates a mini-shockwave, a sonic boom as it breaks the sound barrier. This is the sound which you hear. The whip is probably the first human invention to break the sound barrier.

You might like — W hy do bombs make whistling sound when they fall? The bullwhip tapers down from the handle section to the cracker. The cracker has much less mass than the handle section as you see in the picture too. When the handle of whip is sharply swung in the air, the energy gets transferred down the length of the whip.

The actual decrease of the mass of the moving part occurs simply because the whip ends: the closer the moving bend is to the tip, the less mass is in the part that's moving in the given direction.

Generally, a plank can be much more damaging than a whip. Whips may look cooler, but that seems to be about it. Differences in pain need not reflect the amount of damage done if we can even define that properly.

Soft-tissue bruising, abrasions, lacerations, fractures, etc. I would think that whips are good at bruising and lacerations, whereas planks potentially cover a more wide range of damage. There is a lot of stuff on the internet about surprisingly painful paper cuts , which might also be related somehow. As Alfred said this is because it exeeds th speed of sound. Sounds are traveling vibrations in the form of pressure waves in an elastic medium. In gases, sound travels longitudinally at different speeds, mostly depending on the molecular mass and temperature of the gas, and pressure has little effect.

Sonic booms generate enormous amounts of sound energy, sounding much like an explosion. This is exactly the situation of the whip. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Learn more. Why do whips hurt so much? Ask Question. As the wave gradually moves down into the narrow region, it's moving less mass. So to conserve energy, the wave has to go faster. This is one claim as to how it can build up enough speed to break the sound barrier. The other theory has nothing to do with the whip being tapered.

It says that when the wave goes down to the tip of the whip, it then gets reflected back to the handle. When it changes direction from "going out" to "coming back," it has to go through a very brief, but very enormous, acceleration.