Why is Cracking a Whip So Loud?
Why is Cracking a Whip So Loud

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Cracking a whip causes a small sonic boom as the end travels faster than the speed of sound. Top science bloke Marty Jopson explains the science behind this phenomenon. Subscribe for regular science videos: http://bit.ly/RiSubscRibe The key to how a whip works is the conservation of energy. Any moving object, including this whip, has kinetic energy. Kinetic energy relies on two things - the mass of the thing moving and the velocity at which it's moving at. Due to the uncoiling action of the whip, the mass of the whip decreases through the movement and the velocity increases. The handle of the whip moves at roughly 10m/s but the tip of the whip reaches speeds of over 400 m/s which is faster than the speed of sound at 353 m/s. --- A very special thank you to our Patreon supporters who help make these videos happen, especially: Alessandro Mecca, Ashok Bommisetti, Avrahaim Chein, bestape, Elizabeth Greasley, Greg Nagel, Lester Su, Rebecca Pan, Robert D Finrock, Roger Baker, Sergei Solovev and Will Knott. --- The Ri is on Patreon: https://www.patreon.com/TheRoyalInstitution and Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and Tumblr: http://ri-science.tumblr.com/ Our editorial policy: http://www.rigb.org/home/editorial-policy Subscribe for the latest science videos: http://bit.ly/RiNewsletter


Dane Cook2 : that mustache though

チュimoc : we need the slow mo guys now😏

oolon colluphid : You lost me at 'Miles' per hour

Dylan Parker : this was such a cool explanation - really liked the conservation of energy stuff. never occurred to me before

suraj tiwari : Well explained, Liked the video.

Kent VanderVelden : Absolutely fascinating explanation! The world becomes even more amazing with with just a little knowledge of science. (And I'm jealous the lecturer can grow this much hair :)

OÄKTA DOPBOK : Move em on head em up head em up move em on RAWHIDE

No One : It’s amazing how FASCINATING scientific explanation of everyday phenomenon can be!

Jack Linde : Marty! How the hell have you been? And more importantly, WHERE THE HELL HAVE YOU BEEN? (HINT: We need more Marty videos on both this channel and elsewhere.)

Donald Sleightholme : if you had a array of magnetic induction microphones you could generate a bit of electricity with it (maybe) 🤔🤗

James Wade : All that whip cracking in the lecture space would have made for interesting discussion at front of house at the RI. :)

TheWraithkrown : Marty, I am ok with the fact that you are probably at least ten times smarter than me, but that and the facial hair is too much! Why can't I have facial hair like that?! In all seriousness, thank you for the entertainingly given information.

AA Productions : How loud would it be if you create a small vacuum (like in a bulb or something), and then pop it? How big of a bubble are we talking here? Would it be the same loud? Or is the collapsing vacuum only part of the final sound here?

Wallace McDonut : Timothy Claypole lives on.

Leonardo Cabrera : imagine one electrified and sharped as hell... yeee hee heee

1000Orgasms : Spank it supersonic.

Nivlek : Brilliantly explained.

straydoggio : So it is a sonic boom. + that other thing you said about cavitation bubble collapse. Now you're all set to go on some adventures Dr Marty Jopson, uncovering mysterious ancient relics.

Steve Phillips : Fantastic!

tabaks : And that’s how duck the Quack explains crack and, Bob's your uncle!

James : I need to get one of these for my mistress

xrogaan : That man has style.

NicksWhipShop : Does that whip have an aluminum handle? Great explanation and demonstration!

Jesus Christ : Thanks for making my brain parts feel really nice. Cavitation bubble collapsing, neato!

Tim Landscheidt : Looks like Cody's older brother.

Gonemba Two : My wife is in the hospital =/

Andrew Lankford : Whip it good.

Anita Foster : Is his name quack or bob?!

BananaStab : Great video. and the "duck" explanation was great, I wander though, what the heck is a "mph"?

Víktor Bautista i Roca : In what century was this recorded? Miles an hour? Miles???

Marc Owen : Wot. I always thought cavitation bubbles only happen underwater

Crazy Canuck : The exact moustache you’d expect from an expert on whips.

MrTangerillo : I taught myself how to crack a whip on my own, It was a painful, but very quick learning experience, but I like how this is the Royal Institute and they used MPH, not complaining, just thought it was funny.

Tom Holland : Mo-vember?

mann r : is speed of ripple equal to speed of sound in water

Gunj Chowwiwat : Imagine you get hit by that super sonic whip!

AA Productions : Pretty cool, nice video. (Though the shredding of the newspaper doesn't prove anything.)

ryhisner : This is great, but I think it would be even better if it had included a little animation of the "duck wave" or sounds waves.

Manuel Hartmann : awful

MtB ArN : I got my wife one of these, I regret it!

robby gregg : you forgot to mention the effect of the decreasing diameter of the whip from the handle to the end. The decreasing diameter makes the (cumulative) mass distribution along the whip length from start to end to be non-linear, which, combined with the conservation of energy, further contributes to the speed of the tip. I believe even the varying stiffness of the whip from handle to end also contributes to this. But this is just my $0.02 ...