How do whips work

See Subscription Options. Go Paperless with Digital. Get smart. Sign up for our email newsletter. Sign Up. Support science journalism. Knowledge awaits. See Subscription Options Already a subscriber? Create Account See Subscription Options. As the bend approaches the tip, the mass of the moving part approaches zero while the energy remains relatively constant.

Since the momentum is the product of the mass and speed of the moving object, the smaller the mass, the higher the speed. Hence the end of the whip moves extremely fast, easily reaching the speed of sound. Many published popular science explanations capitalize on the fact that the general shape of a whip is tapered: thick at the handle and very narrow at the tip, hence the decrease of the mass. While tapering does contribute the decreasing mass, it is not a deciding factor. Even "flat" un-tapered whips will crack.

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.

Asked 8 years, 5 months ago. High-speed shadow photography experiments in clearly showed the sonic boom being created. More recently, accelerations of the tip were recorded at 50,g where 1g is the acceleration of a falling object. However, those observations created a puzzle - the tip was moving at twice the speed of sound Mach 2 when the crack was created.

Even though those parts are moving twice as fast, it is the loop itself that generates the sonic boom," Professor Goriely said. The idea that the tip travels twice as fast as the loop is like how the uppermost point on a car tire is traveling at twice the speed of the car for just an instant.

The tapering of a whip makes a loop traveling along it speed up by a factor of ten.