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I Rented A Helicopter To Settle A Physics Debate
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- เผยแพร่เมื่อ 26 ต.ค. 2021
- The story of a controversial physics question on the qualifying exam for the 2014 US Physics Olympiad team. How does a uniform cable beneath a helicopter hang? Visit SimpliSafe.com/veritasium to learn more and to get at least 30% off your SimpliSafe security system! Thanks to SimpliSafe for sponsoring a portion of this video.
Thanks to Scott Smith and the Perris Valley Airport for hosting us. You can follow their social media @skydive_perris and learn more about them at skydiveperris.com/
Thanks to Craig Hosking for being our expert helicopter pilot.
Thanks to Professor Paul Stanley for the interview and for writing such an interesting question.
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References:
The Exam - ve42.co/AAPT2014Exam
The Solution - ve42.co/AAPT2014Solutions
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Special thanks to Patreon supporters: S S, Andrew, Benedikt Heinen, Diffbot, Micah Mangione, MJP, Gnare, Dave Kircher, Edward Larsen, Burt Humburg, Blake Byers, Dumky, Evgeny Skvortsov, Meekay, Bill Linder, Paul Peijzel, Mac Malkawi, Michael Schneider, Big Badaboom, Ludovic Robillard, jim buckmaster, Juan Benet, Ruslan Khroma, Robert Blum, Richard Sundvall, Lee Redden, Vincent, Marinus Kuivenhoven, Alfred Wallace, Clayton Greenwell, Michael Krugman, Cy 'kkm' K'Nelson, Sam Lutfi, Ron Neal
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Written by Derek Muller, Emily Zhang, and Petr Lebedev
Filmed by Derek Muller, Trenton Oliver, and Emily Zhang
Edited by Trenton Oliver
Animation by Mike Radjabov
Music from Epidemic Sounds
Additional video supplied by Getty Images
Produced by Derek Muller, Petr Lebedev, and Emily Zhang
![แฮงแงงแฮงงาม - บอย ศิริชัย [OFFICIAL MV]](http://i.ytimg.com/vi/vCGJTy9ZeP8/mqdefault.jpg)
Pilot: "if it goes wrong it would mean total destruction of the aircraft"
Everyone: ok, lets try it
yeah i wonder how many meetings (and time) and arguments they have to make between everyone, the pilot, SimpliSafe, the filming crew, to get this experiment approved!
I have fewer than 1 friend in the World. That's right. Everybody disses me for making bad videos. I think they are perfect though. Who is right? My dissers or me? Which side are you on, dear alex
Thats all about aviation.
@@AxxLAfriku your channel says something else mister
Derek:
"air friction is not negligible" is the worst statement somebody ever told me
But it is negotiable
It is for some things, like a heavy aerodynamic bomb shape.
This reminds me of an XKCD *What if?* where he states "Well, this is one of the very, very rare situations where bringing in general relativity makes a problem easier to solve."
@@karhukivi Or for that matter a heavy earodynamic atomic bomb explosion if you are near to it.
I made a video solution for this.
Click for a mathematical explanation 😀👍👍
I can imagine someone in the area taking the test and miraculously looking outside to see the answer.
I was there and I saw it when taking the test
deus ex machina
@@Daveeeeeeyhowyoudoing no way
@@PoliticalyEducated he is jokin
Pilots are a very cautious bunch.
For me the most surprising part of the video is not the Physics, but...
That you found someone willing to do all this.
maybe he gave him $20
money.
@@patricksohacki9737 it's worth doing it for $20
not all are as cautious as him to be honest i know a guy flying a crop duster and hes willing to do anything you ask him
@@sirwhitemeat9785
Now that you mention it I really only know USAF pilots.
Lots of trust in seatbelts for this video...
Whenever we do doors open work like this, we have a harness as well as the seatbelt (2 points of contact). It's hard to tell if they're doing something similar here, but you can see something around his outside leg which could be a part of a harness.
Seriously... Was it truly just a single buckle belt? Crazy.
@@MetalAsFork I'd be very surprised if that was all they used!
fancy seeing you here. was surprised it was actually you. I don't listen to any one musician religiously but I've been listening to your stuff on and off since toccata - which is still one of my all time favorite songs. great stuff.
also yeah that man leaning over with nothing but that seatbelt to hold him... he's clearly not been in enough cars to know how often those just don't work.
At 3:27 there appears to be a 2nd belt around his waist. No clue what it could mean.
When i was very young, I asked my dad why the kite string was curved downward instead of a straight line. he said "That's the weight of the string." I didn't quite understand him and thought he said "the way of the string." I spent YEARS with that kind of Zen like understanding of nature in my head.
lol
@@chertfoot1500 compare 1930s Nazi Germany Vs 2020s Communist Chinazi IN YOUR NEXT VIDEO Project before it's too late
@@matpk Yo CIA come get your bots I think they’re broken.
i love this
“The string that can be strung is not the eternal string”
The pilot is a personal friend of mine...great guy! Funny to stumble onto him in this video. I've flown in his helicopter :)
😕
Cap
@@Buttercup7889 why would they be capping about something so trivial. People like you ruin the internet
@@Buttercup7889 bro stuck in 2021
@@Buttercup7889 I prefer Spiderman
Veritasium is the type of person that when he gets a question wrong on the test, he spends $10k to prove them wrong lmao
Not a lot of money for them though, with all the revenue they get from their videos
He attempts to anyway, his methods in every video are wrong. This guy is a physics version of Scopes fact checking.
Getting a "we need to talk." message from your girlfriend gives off the exact same vibes as an "air resistance is NOT negligible" statement on a physics test. You might be 100% sure you did nothing wrong and still you will feel insecure about it.
I am worried:
If Genetics evolve and dangerous people like 'Autism Speaks' (generally seen as an enemy
of autistic people) is never stopped... will both issues... eventually fuse?!
@@nenmaster5218 what the hell are you talking about
@@nenmaster5218 what.
@@nenmaster5218 no
@@nenmaster5218 maybe.
Derek wakes up in the morning and says, “you know what I need a helicopter today“ and then makes it happen to make us smarter👊👍
To the person reading this comment you are awesome & hope you having a great day
My dream is to hit 30K I hope you can help me accomplish my dreams.
I uploaded my Face Reveal.
I created a video solution for this question and yesss it's correct.
Click my profile for a theoretical explanation !
@@Candority how is this a question
@@LightningSquad you had us in the first half
The feeling of superiority you get from answering the theoretical questions in a veritasium video correctly is far higher than any other feeling in the world
Can’t argue with that, but it’s also just as important to accept when you get to a wrong answer.
Hi Derek, all I wanted to say was just thank you for having a very sensible and non-intrusive approach to sponsorships in your videos.
i love how the teacher is like "this is hard AF to answer, i dont think even i could get it right, lets put it in an important exam, it will be FUN"
Right? Like wtf. If someone with a masters degree is wrong how do they expect 18 year olds who don’t even wanna come to class to get it 😂
It's for the US Physics Olympiad entrance exam. Those kids are ridiculously smart.
"Let's increase the fun by removing the weight"
@@jeninjose911 oh kinda nvm then, for some reason I was comparing this to the ap physics I took in highschool which I’m sure is very different then this 😂
He said counter intuitive. Everyone taking that exam should have the tools to answer this question even if it's against their intuition.
This is one of those physic questions where I would have the right answer on my first attempt, then second guess myself after reading the question for the 10th time to make sure I wasn't overthinking it
Under thinking
Sure ur overthinking it when most people have a challenge knowing what it is and haven't seen it in real life before, but yeh, ur overthinking it like the question is easy
@@raymondqiu8202 I mean his first answer is probably just instinct or feeling, then when he starts thinking about it and visualizing it in his head the answer changes
Veritasium, is a great video show. But at the university I attended, that question would have been a composition question and all of the answers shown would have been incorrect. You would have to have pointed out that the shape of the rope does not change by hanging it out of a helicopter. By stretching it, possibility it could have gotten smaller around but the shape would not have changed. The pictures drawn were only a distraction to keep someone from reading the question how it was written. Most Veritasium videos would have never overlooked this point.
@@bradcollier7249 Sounds like a great way to turn a mildly interesting question about how forces act on an object into pedantry.
Basically all wrong. You could have searched for a*cosh(a/x). First flight a is just very low. That’s why bridges are made in that shape. You could have safed the money by simple research:/
That Pilot seems like such a nice guy. He was really into the experiment as well, rather than just flying.
he was paid generous
@@hotaru6765 u know how much gas that thing cost, plus training, and stuff , i mean, the pilot should have a TH-cam channel
You heard how many hours flying he had. Flying would be like walking for him probably where doing all this stuff he was told never to do... THATS exciting...
@@christopherboyle2403 Yeah, nothing like doing your daily job for however many years and finally get something that isn't the same routine over and over
@@Toastmaster_5000 vast majority of piloting aircraft is "maneuver so your passengers dont spill their drink" and it is boring. Pilots love doing more interesting stuff, its true.
“Interestingly no one chose E”
Me whispering sadly: *”I chose E”*
Well if your put a parachute in the middle and a weight at the bottom I think it's gonna do shape E
I'm with ya brother. Together we weep
I chose E as well :)
I chose E cause I thought it was the most counterintuitive so must be right :(
If it will make you feel better, there is bound to be a rope out there that feels like doing that shape, and is just waiting for its chance. It appreciates your confidence.
I whish I had a physics professor that would go to such lengths to prove a concept
dont we all wish our teachers could rent helicopters lol
Well you'd need to find a teacher who makes enough to afford the rope
eyy rocket man
ok cool comment but how do you misspell uujicsh
Hi Integza! Please make a 3D printed frog costume for a cat this Halloween
"The proof is left as an exercise to the reader"
The reader:
😂
horrendously underrated comment
LOL
Lol
SHEEEEEEESH!
"what would be the risk of my veritasium flag idea?"
*'complete destruction of the aircraft'*
"ok cool lets do it guys"
They put a smaller flag
Compare 1930s Nazi Germany Vs 2020s Communist Chinazi IN YOUR NEXT VIDEO Project before it's too late
@@matpk Are you sure you are spamming this in the right vídeo, bot?
@@matpk They have nothing in common, that's what they have 😂
@@Gabriel-yd4bq
-Both are one party states
-Both persecuted a religious/ethic minority and concentrated them in camps
-Both practiced state-mandated eugenics programs and population control
-Both punished political dissidents
-Both used the legal opinions and philosophy of Carl Schmitt to justify power grabs and expansion of state authority
-Both have similarities in the treatment of The Free City of Danzig/Gdańsk and Hong Kong Special Administrative Region
" that's neat, it could make a good multiple choice question" is something only a die hard teacher would say
More like: "Thats a difficult to reach and counter intuitive conclusion to make, those suckers are never gonna get it right"
Everything in the universe is a potential multiple choice question.
A real die hard teacher would say "Yippee Ki-yay MF'er"
@@leoleo7047 that's how the dumbos are filtered out among intellectuals.
So nice to see Derek back to his roots - polling random people on the street (so to speak). Just like "how far away is the moon" and "which object is colder".
The moon is a myth. There's no such thing.
@@DP-ot6zf yes truly
@@DP-ot6zf
Yes there is. I have one.
@@DP-ot6zf Funny joke
It’d be nice to see some content like that but I quite like the direction he’s gone now and I definitely don’t want him to turn to just that.
Him in the future: "going into a black hole to settle a physics debate"
🤣🤣
How will he return tho? 🙄
Him in the video from before channel creation: "so this finally sets the 2088 time travel debate."
@@Ponta-Kun_Official It would be a clickbait title, cause he wouldn't.
I know
Classic physics teacher/professor; goes on hike in nature, comes back with difficult exam question.
Lol
That's not a difficult question, a child would get it right without hesitation
In fact it blew my mind how easy it is and how in the world it could make its way into qualifying exam, thats basic inertia, anyone who ever been in the moving vehicle can get that right without any physics background.
@@Roman-kk1ic funny thing is that the explanation did not have anything to do with inertia
@@Roman-kk1ic How is it basic inertia?
I feel like my insanely low understanding of physics led me to the correct answer. Thank you brain for that one.
now I feel like an idiot even tho I got (guessed) the right answer :(
lol, me too. good at mathematics, terrible at physics.
It's not your fault. This is one of these questions that shouldn't be present in any sort of exam because there are just too many different factors for there to be any logical conclusive answers. Seeing all the controversy that naturally spurred up because of it, it's no wonder our education systems today are complete f*cking jokes.
@@Coecoo It's not controversy, it's debate. The right answer is clear from this demo beyond reasonable doubt and you could conceivably work through the same reasoning in an exam to arrive at the answer. So long as the premise is laid out clearly this is not a bad question.
Oh you mean common sense?? Lol
"how's it feel when it's dangling?"
"No lateral displacement at all."
Feeling's mutual.
obviously you forgot to factor in sticking to the thigh.
🤝
💀👌
@@bubbaguy4411 widen the legs, my friend. Widen
WTF is going on here?
Now add the parachute to the middle of the rope with the kettlebell at the end to get answer E.
Or answer F, a crash press F to pay respects
and fly the helicopter in the vacuum (lets think that helicopter rotors would work in vacuum) and the answer will be A
@@PedroHenrique-ig6cw The answer is A if you are in the correct field of view. ALL of these answers are correct because it doesn't account for speed.
@@stormrungaming "Constant speed"
@@bobzombie2710 Which constant speed?... If the helicopter is going at .02mph constant.. the rope wont budge. If it's going 200mph.. the rope will be straight behind.. even with the weight. Like I said.. It doesn't account for speed.
This video is giving me MythBusters vibes.
Except they didn't blow up the helicopter at the end...
The best kind
Its about time we had someone to assume that mantal.
@@Hexstream but they were talking about the helicopter blowing up the whole time which was reminiscent
And in proper Mythbusters fashion, they quickly jumped to a conclusion after a single test. What about a longer rope? A short segment of a curve will always appear straight. But my biggest peeve about this video is that he used such a ridiculously heavy rope, which, of course would have very little effect from the vertical airflow of the propellor and called it done.
Pilot: “there’s lots of ways to die by doing this”
Everyone: “okay, cool. Let’s go”
Yeah.. Hes a bit dramatic 🙄..
me: "why a _helicopter?_ "
They could have just used a drone
@@bci. they wouldn't be able to find a drone capable of carrying such a large rope, they'd also have to rig a detachment system, and probably also get permits to fly the drone.
@@lunalu9117 they could have used a small rope
Teachers: ‘the exams aren’t trying to catch you out’
Guy making exams: ‘This looks counter intuitive - this might make a good question.’
Edit: You guys are taking this way too seriously lol
Other teachers: “Nicely done.”
haha yes
To be honest to me that seems like a terrible question if it's just multiple choice without any explanation.
@@federicoscrinzi3552 Not really. This is a qualifier for a competition, not an exam in a school. To me, as someone who've done competitions like this while in school and focusing on physics specifically in school and university, B was the obvious answer. It's not immediately clear that a stable solution exists at all - that's a much harder problem, but if it does, it HAS to be B, as that's the only option that satisfies balance of forces and symmetries necessary for stable solution. So you answer B and move on to the next question. This sort of thing is more about being able to quickly discard bad options than any sort of rigorous solution.
@@konstantinkh ah I see! If this was a competition then I agree it's a good question
Professor: "This is completely counterintuitive. Let's put it as a multiple choice questions to my students on a selection test."
Makes sense to me; better than having a bunch of questions that are intuitive and therefore answered exactly the same way by people regardless of whether they have an ability to break problems down and think them through...
That's physics bud.
Like 99 percent of physics is counterintuitive, that's why it took so long to figure out.
This is not a regular test. This is for a physics Competition. Challenging it must be.
@You are correct But It's not like there are any other possibilities.
I've seen this experiment numerous times while piloting helicopters in Arma 3. The game perfectly simulates the unweighted and weighted experiments. Quite incredible imo :)
no way fr?
I miss arma 2 dayz :(
damn
@@dilkush_21 don’t tell me what to do
Team Gamer
What I like the most about this video is that it shows that realism rules; we can model the rope, the air friction and make predictions all day, but nothing feels more satisfying than seeing reality confirm our prediction.
Right
More importantly if reality does not confirm to our prediction ;)
I agree with the sentiment, but I think what you’re praising is the scientific method (or perhaps empiricism generally), not realism. One can be a realist (committed to an objectively existing “real world”) while at the same time rejecting science as a method for acquiring knowledge.
that's why going full sheep in science is a brain dead move
"Sure it works in practice, but what about in theory?"
As a physics student, I love that you took a question and practised it in real to find the answer. I'm sure every physics/engineering student will appreciate this video
Compare 1930s Nazi Germany Vs 2020s Communist Chinazi IN YOUR NEXT VIDEO Project before it's too late
@@bikashpatra what do you need the pan for?
@Kishore Anand no one asked
Helicopter pilot: explains dangers of flying with a dangling rope beneath them.
Derek: ooh now can we try it again with a flag?
Helicopter pilot: yeah so that's less safe.
Derek: ooh now can we try it again with a parachute attached?
Helicopter pilot: ....
Glad you all made it and thanks for the awesome video!
I mean, at any given point the pilot could have said, "No." He pointed out the risks for the sake of informed consent, but ultimately felt like he was willing to take them so long as the passengers were also willing to take them.
@@RayneAngelus I'm sure he was a military pilot before.
Well to perfectly copy Mythbusters Derek would have to blow up the test until the helicopter blew up.
There was never any serious danger. They extended the rope from an airborne, stationary position. Wash from the main rotor is nearly 100% downward. Only near the ground would you have turbulent upward flow and only when moving forward would you be in danger of entangling the tail rotor. If the pilot thought there was any real danger, he would not have attempted it. They just put those comments in for dramatic effect.
The Answer is.........OH HELLLLLL NAW!! Those side steps on that choppa need to be at least 12in wide before imma put my leg/foot outside!!
OH!! AND PUT THE DAMN DOORS BACK ON!! THIS AIN'T NO DAMN JEEP!! {0.o}
😆😂🤣
I would have never imagined as a teen that I'd be enjoying studying because someone on TH-cam made it enjoyable. Thank you!
Oh, yeah, i HATED physics and all the talk about "forces" as a kid. Now I binge these types of videos because of presenters and science promoters like Derek.
I want to develop a way to kinda revolutionize some forms of learning, but i need help to pull it off. I genuinely think I'm onto something brilliant, but It's super hard to approach the people who can make it work without some form of proof of concept, so I'm literally going to school to learn some software in order to make a basic version to use for that purpose. it's frustrating that i have to jump through these hoops.
yeeesssss
رامي
i just got 900 iq after this video
Do you remember the thought experiment about 2 spaceships moving at speeds near speed of light, that shoot a beam of light to each other? Soon, time will come for Derek to order 2 spaceships.
I’ve heard the one about two spaceships moving away from each other at .5c but I haven’t heard that one; how does it go?
@@motetotee In this experiment, two spaceships move parallel to each other. One shoots a beam of light towards another. From the perspective of an observer on one of these spaceships, the light travels straight path which is perpendicular to the direction in each the ships are flying. While observer who is just standing near by, sees that light travelled through a diagonal path. Light travels different path depending on velocity of an observer.
another one about two spaceships with a picture frame moving near light speed in one and another observing. Derek will soon test that one too 😂
I literally had this on my relativity test a week ago. Well I know I got that one wrong.
I remember the Bell's spaceship paradox asking if a string tied taut between 2 spaceships accelerating from rest to near C will break.
I was like "I'll pick C because it's intuitive, but in the back of my mind I think E is a real possibility". Yeah, give me two shots and witness me miss both.
Intuitively i said B (diagonal) cause it said "constant speed"
@@flavioplb5490 I made a video solution for this.
Click for a mathematical explanation 😀👍👍
Derek:"Interestingly noone chose E"
I was like:"Me, me, I chose E, am I smart?"
No :D
From intuition I took C too, but then I thought "Wait, this is like when people jump (5 guys jumping, one on each end of the rope swinging it around). If they stop the swinging (and the jumpers are out fo the way) and just stand still, the rope will balance itself out, whatever strange form it had." And choose the straight line, where everything is balanced out.
@@flavioplb5490 wait, but if it's a constant speed then that speed could be 0, and in that case it would be A
Bottom line: never let professors wander into the outside world letting them come up with new problems
Students sould be checking their prof's social media to see where they went lately, trying to predict questions!
It's unfair. He knows the answer cause he observed the damn thing. Would he have come up with the answer by himself? Likely not? It'd have been just a guess. But how dare the students not know the answer to this question, all on their own, based on what they study in the classroom. Mean AF.
@@luckybarrel7829 Literally just 3 forces on the rope. You don't have much trust in professors' understanding of physics, do you?
@@chris4231 Did you even watch the video where the person who came up with the question admitted he knew the answer cause he saw the damn thing happening
@@luckybarrel7829 He came up with the problem by seeing it. Doesn't mean he wouldn't be able to solve it. However i will admit that i forgot about the wind generated by the helicopter's. This part might be impossible to figure out without a real world experiment.
Normal students: *making equations, imagine the problem given*
Veritasium: "Lets go on a HELICOPTER*
yeah, he could've just used a drone😂
Calculations and simulations withouth practical experiments are worthless
He could have used a drone, yes.
But then again, 10 million subs. Go all in. Renting a helo isn't that expensive
I like how the pilot keeps saying everything they're doing could destroy the aircraft and cause them to crash but then proceeds anyway. LOL
His wife made him do it lol
That would actually make me feel better if I were working with him. Here's this pilot who's constantly thinking about how something could go wrong, then making sure it doesn't.
He’s actually hoping it kills him.
That just means that it will not happen but let me say that to make the video and myself look better.
@@AngryMangrove there was no making sure, it was just hoping it doesn't lol
Derek: What would be the real risk?
Pilot: Both rotors
Derek: So anyway, I proceed to hang the Veritasium flag
lol, pilot was way more nervous than necessary. Good quality to have in your helicopter pilot. :)
- And a parachute.
@@josephm.6453 Why? The pilot could easily sue Derek if something would go wrong.
@@josephm.6453 Probably more worried about the helicopter crashing and killing everyone inside.
I made a video solution for this.
Click for a mathematical explanation 😀👍👍
I had no idea this question went viral after we published it! But I'm glad experiment matched theory. And to everyone who said we should have directed students to neglect the rotor wash, I completely agree. You try to eliminate as many gotchas as you can in editing, but you can never get them all...
oh hi prof!
Professor, Did you already knew the answer?
The thing that got me was I expected there to be a moment around the helicopter from the wind, making a parabolic curve so it would be C but that would only be if it were accelerating
If you consider an extremely long rope and high flying helicopter, the answer would be C since the atmosphere would be less dense at the top of the rope and more dense at the bottom, giving increasing drag per unit area as you move down the rope. Neglect atmospheric density due to altitude - one more gotcha to remove?
@@Indic-D I'm not a professor. :) And I had to work it out when the question arrived in my inbox, just like any student taking the test.
physics is so counterintuitive
yeah
I actually feel the opposite statement, that it was rather intuitive. I haven't done physics since highschool (10 years ago) yet the answer to me was logically B) for the reasons the video described. Same for the weight and parachute experiments.
@@json_bourne3812 I figured it'd be B but thought it'd be a different answer cause B was too obvious.
physics is intuitive. it’s the most logical science
@@arthurmint - Depends on which part of physics you are referring to. A lot of people thought that a 2 lb steel ball would fall faster than a 1 lb steel ball. Diffraction of light as it moves from air into water or glass is also somewhat counter-intuitive. Of course when it comes to electrons and quantum physics things really get weird since there are so many things such as particle-wave duality, Heisenberg Uncertainty Principle and quantum entanglement of particles that no one yet today really understands.
I love how my inability to understand the rotor wash meant that I totally ignored it on the poll and got the right answer.
LOL eh most times the simplest answer is the right one.
I'm in this comment, and I like it 👌🏻
“Air friction on the cable is NOT negligible.”
Engineers : Impossible
*physicists
@@unity_talon thnx for ruining joke
Rather, the alternative is true in this case
@@unity_talon Both
@@unity_talon you mean
Fisikist ?
I love how the answers to this come from high school physics, but the nuances on the problem setup can be hotly debated by some of the best physicists in the country
What is "a perfectly flexible uniform cable"? God's favourite method to get out of the bedroom when his wife is sleeping?
This question is common sense. I cannot believe these dopes had to rent a helicopter to understand basic physics.
@@411Adidas Obviously not 'common' sense, since college students, professors, scientists and generally intelligent people can disagree. There are many things in life that you may think you know the answer to, but the only real way to know the answer is to experiment. In other words, what works is what works, theory be damned.
@@tclem44 Yes, complex questions need testing, but this is high school level physics and very rudimentary.
If you didn't get these three versions ( rope, weighted rope, parachute) of the question right in 5s, than maybe you need a refresher in basic physics.
@@411Adidas You obviously failed common sense then. Who doesn't want to rent a free helicopter? Also if he didn't rent the helicopter the video wouldn't get nearly as many views. He rented the helicopter for fun. (If he really couldn't figure it out how to calculate it. You can find videos online of ropes hanging from helicopters).
I was thinking the guy would’ve said:
“I worked all my life with helicopter and nobody asked me this damn question”
😂
The pilot is so chill. Ice in his veins. 🤘
Chopper pilots are, they have to be. :-)
"Blah blah blah destruction to the aircraft."
Sheesh
@@NickWestgate It might cause destruction of the aircraft...
Let's try it.
Answer is wrong. Since it's clearly mentioned air resistance is not negligible, rotor wash however insignificant have to be considered. This means even though it appears diagonal it is slightly curved.
So then the right answer is indeed C as it would ever so slightly and imperceptibly curve
I love how physics is so counterintuitive in so many apparently trivial problems. I chose C for the initial problem, and I have a degree in astrophysics.
I’m an engineer specialising in fluids and I also chose C!
@sp4nrs haha did you do that because you were assuming the rope to be hovering in some sort of a boundary layer?
I still think it's C, only the curvature is VERY light. If the chopper were MUCH heavier and/or the wingspan was much smaller, the thrust on the blades would be MUCH stronger, becoming a more notable factor/effect. The rope would never be totally vertical, not even at the top, and the curvature varies through the length of the rope, being less pronounced as you go down.
@@xxrgxxcasco Idiot, accept your defeat with some grace.
Physics Bachelor and got B :P
I love how last 2 examples are so easy and intuitive, while the 1st one is so confusing.
The proffesor who suggested to remove the weight managed to screw over so many students with that slight alternation.
The first one is not only confusing, it suggests you have to neglect one of the forces on the force diagram. Had the question said the propeller wash is negligible, it would be a much better problem.
It’s not screwing anyone over when it’s literally physics lol
Screwing someone over involves something unfair but physics is by definition “fair”
They didn't screw anyone over. They stated all of the pertinent parameters necessary for the students to balance the forces and deduce a solution.
@@bermchasin that’s a good point. Most people wouldn’t happen to know that propeller wash dissipate quickly
@@bermchasin you would only state that the rotor wash is negligible if it were a hypothetical statement. In reality, the rotor wash is negligible. Certainly, you would have to have personal experience or prior knowledge to consider that, but that adds a more challenging aspect to the question.
People who said B on the TH-cam poll:
*signature look of superiority*
Except its D since the test said weight.
you damn right
@@Laroac But not in the poll 🤷🏻♀️
@@Laroac lol it doesn't even say weight on the test. Pause the video at the beginning
Also, it's not relevant because the TH-cam poll didn't say that either.
"NOT negligible"
... Every physics student starts to sweat.
What do you mean a cow isn’t a perfect sphere with uniform density???
What an amazing thought experiment. I first started thinking about this issue while reading "Through Gates Of Splendor" by Elizabeth Elliot.
Hi
yo
third
Can you make video about delta P?
Can I ask you why this book brought up this issues?
I picked B because it felt correct, but that's probably due to me having watched helicopters with sling loads in person before. Great to see the actual explanation behind it!
I have worked up north for a few years, and most equipment going off-road is transported by huge helicopters (diggers, material for camps, etc.) So I've seen lots of helico transports coming and going. They used a huge rope, like a ship, and the loads were heavy (much more than 20lbs). And each time, the sling was in the C shape.
me too but never have even seen a helicopter up close
shouldnt it be in the D shape if it has a load attached to it? B is only for a cable without a load
@@nicolasfisch2794 the farther up the cable you go the more tension is on the rope, it'll be straightest at the helicopter
@@nicolasfisch2794 google for aerial firefighting helicopters. They have a bucket of water hanging and while moving the rope takes the b shape.
There is not one correct answer. Probably it depends on the weight and the distance between the helicopter and the weight. But I am no expert (in fact I am the exact opposite) so dont take what I say very seriously.
I was really looking forward to this video after answering the poll. Spent some time running around the apartment with a rope in my hand to get an idea about what is going on :D
I stole my nephews air hog and tied a rope to it
Have you sucked out all the air first ? ;-)
Yeah, that's us, typical YT science freaks... :-D
Did the same thing with a piece of string
Same 🤣
The teacher that said “lets make it more fun” is a god damn gangster gg my boy
More counterintuitive = more fun
It's the meanest thing I've heard today
@@marquesghm I don't think it's mean, it's a good way to test learning. In a many real jobs, you would have to think about cases that don't 100% line up with the textbook. Memorizing what are the answers isn't as useful as understanding how to reach the answer. Yes this is a difficult to reach answer, so the teacher has high expectations for the students.
@@chrisportway I agree, but in a test its far from fun. The fun way to teach this is by a pratical example like in the video.
@@marquesghm It was not part of a test.
@@marquesghm honestly I though this was intuitive, but the weighted inverted J was counter intuitive.
"Air Friction is not negligible"
Students, about to assume helicopter as sphere: *Impossible*
or a box
So an engineer, a mathematician and a physicist go to a horse race. They find out that large sums of money can be made by betting on which horse will win. "We're intelligent people. We can figure out which horse will win and make lots of money. Let's meet up in two weeks and discuss our findings."
So two weeks later they meet up again and the engineer goes first: "I looked at all the charts and Tables and could not find one for horse races. I think the problem can not be solved."
Mathematician: "No, no, I've proven that there has to be a solution. In a race with a finite number of horses, one of them must win!.
Physicist: "Yes! I even found the solution! I can predict which horse will win! At least for spherical horses in a vacuum..."
I made a video solution for this problem.
Click for a mathematical explanation😀👍
@@Benjamin-xv9le I made a video solution for this problem.
Click for a mathematical explanation😀👍
But still I didn't expect that to be straight.
I'm just glad it wasn't E. Also, that pilot is such a boss, perfectly hovering a helicopter while hanging his head out the window looking down at the rope.
I don't think that's much of a feat for pilots actually. Those guys are FOCUSED. I've seen TH-cam videos of pilots in training stalling their plane and not panicking whatsoever while they were hurtling towards the ground. They don't panic and correct the plane instead
I think it could have been e if they put the parachute in the middle of the rope and the weight on the end or something idk I think e could be possible to replicate
@@apttewly you've seen a youtube videos? ... huh.. interesting.
That's one hell of a pilot.
I was an Air Force cadet(Civil Air Patrol) and the first thing they taught me before getting in that cockpit- "You have to stay ahead of the aircraft, plan and know where it's going before it's going there. If you get think of what todo after it's happening you start reacting instead of planning"
I think this makes it more intuitive: I considered the same scenario but under water and the answer seemed a lot more clear in my mind than in air, it's exactly the same scenario just a higher density fluid.
this also also why i knew the answer from watching my goldfish swim with poop hanging out his ass
@@Predator23321 jesus... lmaoo
Thank you. Lot better visualization
So what's the answer?
Asking for a future goldfish owner 😂
@@lillyanneserrelio2187 Depends on whether there's a stone or a small parachute at the end of the poop, clearly!
I work at an airport, so I see this in action every once in a while when the police department practices “long lining” for search and rescue missions. It’s cool to now see the science behind how the cable hangs
I worked ATC at a military heliport, we call them "slung load" ops.
An amazing counterintuitive fact.
But as a teacher, I would never use something like this in an exam, especially in an admission test. This clearly worked just like a lottery.
Being graduate-level, you might expect that people would actually derive it. You would have to include a "ignore rotor wash" disclaimer though.
The question was posed in the context of a contest not an exam.
It’s not like 30 students turned to page 2 and read that as a question.
In highschool, we got a much harder problem in a test which even the teacher didn't realize was unsolvable with highschool math. In fact, it's not even possible to solve it analytically. The problem was about a pendulum made out of a spring. The teacher just assumed the usual facts (e. g. velocity is horizontal under the suspension point) and solved the problem based on that. I immediately recognized something was off and wrote a small program that simulated the kinematics of the system. Turned out, the teacher's assumptions were not valid. Unfortunately, we couldn't convince him of this fact.
@@viharsarok Man I relate to this too much. Those problems so ridiculous not even the teacher knows how to solve them. But they're in our exams. Without calculator and with time limit.
Nah they’ll sort it out
It’s a great feeling to be proven wrong in such an interesting and engaging way.
In a debate, the person who turns out to have been wrong generally learns more than the one who was right.
This is why physics fascinates me, because I have no gift of intuition for it. The actual results always surprise me.
May I recommend that you stay away from extreme sports? Not having a good intuitive understanding of, at least, rigid body physics can be detrimental to your safety and health when it comes to extreme sports...
@@andersjjensen that's some random advice nobody asked for
@@valerierodger7700 Plus he's a professor in physics, so if it's not intuitive for him - laymens intuition wont be better than that.
I was wrong too, thought rotors will impact rope right below the helicopter
@@valerierodger7700 I think you have to be a student of physics to predict these things... Without other, we think the world is flat 😅
There is a harmonic oscillation occuring in the rope too. The tension is lower away from the copter hence the frequencies are lower and amplitude is higher. The tip of the rope is free so there's an antinode there, thus the high amplitude, so it's flipping between exp graph shape and log graph shape.
That pilot is the will hero here 💯 those skills allowed us " you & your team to be specific " to take this question to the fields in come to a conclusions ! Great work & love the content !
Can we just take a moment to appreciate the transition from real life helicopter to 'the answer is B'. Beautiful editing.
Damn, spoilers
@@brixan... don’t look at the comments before watching then
@@additionaddict5524 don't tell me how to live my life
@@brixan... no problem, bond dies at the end of the film.
@@additionaddict5524 which one?!?
the pilot seems like a pretty chill dude to hang out with
no he seems really self absorbed
The rope agrees
Insert Peter Griffin gif here
@@jlee-mp4 so do you
Pilots are all pretty chill, we worked hard for our positions so no point in adding extra stress with arguing
Happy to see a mainstream channel discussing a Physics Olympiad Problem and that too so nicely
Would love to see more of these !
Fun video as usual. Education, when done properly, is the best form of entertainment.
Not going to lie, I was half expecting a weigh in on the Steve Mould/ElectroBOOM debate.
Exactly what I thought. I wish it had been. I guessed this one correctly out of the box so this one was boring.
"Let's go!" Said Derek as he jumps into the passenger seat of an empty helicopter.
And it was at that point he was reminded that he has no friends, and upon being hit by a wave of crushing loneliness, he took off only to slam it into the ground. RIP
Well, he can always make helicopter noises in the passenger seat of an empty helicopter.
Makes sense. Easier to get the audio from camera takes with no engine noise. But yeah.
No thats wrong, he took us all with him
My guess was E, for what it's worth. But I don't know much about helicopters, so I was factoring in the downforce from the rotors, which as was explained in the video, is pretty much a non-issue.
I'm also not a Physics major, so there's that.
Good
Im a physics major and it was obviously B and D in the two scenarios. Really surprised that this is a "challenging" question to some pysicists
@@seankrolyk5814 Could you please help me understand that why in 8:40 the air resistance is increasing as we go up the rope whereas it was constant in the other two cases ?
@@Guri_Veera it's explained at 5:00
I put E while taking the test; I thought air resistance would act equally and make it a straight vertical line at a constant velocity other than near the helicopter.
Great experiments! Definitely going to show to my physics class. 👨🏫👨🔬
Well I guess my name is "no one". Definitely chose E. Definitely was wrong haha.
Don't worry man I chose E too haha. Guess we just think outside the box, yeah I'll go with that.
I overthought it, assumed it was a trick question, and picked the one I'd be most surprised to learn was correct. A poor way to try to be right, i now find out
Likewise! And I thought I was correct when I saw the very last couple inches tipping down! Maybe the rope wasn’t long enough? 😅😂
Same here, pretty cool video though, wasn't it.
I made a video solution for this problem.
Click for a mathematical explanation 😀👍
Neat experiment. As a non-physicist the “weight” + “parachute” shape answers for me were immediate, intuitive and seemed obvious but *not* the first one, the rope by itself…
Great fun video!
The correct answer would have been (F) impossible to say without knowing the length of the rope and the rotor wash speed to forward velocity ratio. You've got downward wind from the rotors and wind from the forward speed. As the length of the rope increases, some of it will eventually fall outside of the rotor wash (losing the downward wind).
@@Mr.Ekshin He actually mentioned that the downward wind from the rotors wasn't actually relevant.
I love that counterintuitive aspect of physics. All variables must be considered, then reconsidered over and over until the model/solution is exact/correct.
"How does that feel while it's dangling?" smiling.
"Feels pretty good. How is your forearm doing?"
"I'm feeling good. Gonna feel different when I have to pull it up."
-Veritasium (2021)
Also no ”lateral displacement” at all. Someone should work that into a pick-up line.
The dialogues sound like they come from Grand Theft Auto
veritasium when the experiment is done: ok i pull up😎😎
@@xyhmo LOL
@@poodle5421 Right. I shouldn't have left that one out.
I love how the teacher is like, “this is really hard to answer, I don’t think even I can get it right. Let’s put it in an important exam, it’ll be fun”
@@AakashKumar-gt9ip alright bud no need to be rude
@@AakashKumar-gt9ip He never said he couldn't solve it, but he basically admitted he based the questions on events he experienced and not events he conceptualized and solved using math.
EDIT: It's not a bad question, it's just more of an engineering experience question than a mathematic question.
@@SekiberiusWelkesh that's suppose to be a physic exam right? Not an engineering exam right? That's as bad as an IQ test in foreign language that you cant understand.
Norm MacDonald was right about teachers. Confirmed! :)
@@nyang4276 Nah he's wrong it's definitely still a physics question. Just because the problem came from a real world observation doesn't make it engineering especially considering nothing is being made here. It's entirely an analysis of forces along the length of the rope which is physics.
I honestly thought it’d be b but have a curve in the last roughly 1/8th of the rope where the air resistance had overcome the downward force towards the bottom. Really interesting to see
Great video. I loved seeing these multiple choice options replicated in real time. I guessed C (wrong) with the plain rope scenario.
"Rotor wash doesn't extend that far below the helicopter"
It sounds like the entire question relies on the knowledge of this aviation trivia to actually complete, how mean
@Ishan Pant Yeah, as a physics major, if they had specified that the rotor effects could be neglected, I think the solution would have been immediately obvious to me.
It also means that the helicopter could be substituted with a small airplane making the actual verification safer!
I got it right, and I didn't even consider this
Yeah, when I first saw the question rotor wash didn't even occur to me and so I answered B as it seemed the obvious answer to me. (Physics student here.) When I saw people mentioning rotor wash in the comments I immediately started second guessing myself. But being correct in this way is immensely unsatisfying because I implicitly made an assumption that happened to be physically realistic purely by chance.
Yes it is, but that makes the difference between knowing and understanding phisics. So why it is negligible for a a helicopter and definitely not for a jet engine? Because of the structure around the blades in a jet , that keeps the air confined, and actually creates a jet. And to top it off, you forgot that between the propeller and the rope there is actually an obstacle too: the body of the helicopter.
But let's say that the downwash is important enough. Do you think that it goes perfectly vertically down? Remember, air resistence is not negligible so something has to compensate the air resistance of the helicopter body moving forward, otherwise the helicopter will slow down, even if it is moving at a constant speed.
"Interestingly... No one chose E."
I Did! I chose E on that bell curve graph. I was just wrong.
That's good, at least *someone* felt responsible for saving the bell curve! ;)
Same, I feel dumb for overthinking it 😅
I picked E because I thought the downward force from the rotors would also be nontrivial, pushing the rope downward toward the top, similar to Derek's initial thought.
If it were longer and prop wash were stronger... ;)
I picked B! I feel smart (for now) even though I was just making an educated guess lol
when I was initially presented with this question the weight and length of the rope as well as the speed of the helicopter where not specified which I thought were all important factors as a lighter rope at lower speeds might actually manifest the more intuitive answer. while that same lighter rope at speeds sufficiently high would be practically horizontal to the ground as the wind from the helicopter moving forward would completely negate any effects the wind from the rotors themselves caused.
It's just like a ball and string, the ball at the end of the string lags behind the string as it's pulled forward.
I think a lot picked "C" because it would likely look like that whilst accelerating, but at speed it would be "B."
That’s why reading the question is also important. I got the second question wrong because I failed to take into account air resistance, while getting the first right by reading that it was at a constant velocity.
But the whole rope has to accelerate, the top of the roap being pulled forward with the helicopter, then the bottom being pushed back with air resistance, it would be the same scenario, the rope would always be in a straight line, though flexible. You assumed that for the same reason the majority assumed "C", because it does look like that's what would happen.
I'm not convinced. I think Derek's explanation is lacking something, the sheer weight of the rope makes air resistance negligible, a lighter rope could reveal answer C to be correct, and the majority of people don't just pick C because they're dumb, but because of experience.
I think he's lacking the pull of the rope on itself. The higher the point on the rope, the more rope and thus weight below it.
With the rope as heavy as 20lbs the air resistance on the lowest point becomes negligible compared to the weight.
Also I wonder how the rope would behave when the helicopter were moving through a vacuum.
Hm... Somehow I don't expect anyone here to have a discussion about this. Only giant explanations how everyone thinks he's right. Why's that, I wonder...
@@nightmareTomek I seriously think you’re exaggerating the general populations understanding of physics. There’s lots of examples of people getting forces on an object wrong because they just pick what they observe the forces to be. An average person who hasn’t studied physics in detail will answer a lot of these questions wrong. Nothing wrong with that either, most people just don’t study this subject that deeply. Nor do they understand or even take into account weight of rope or know how to account for air resistance. As for people disagreeing, it’s TH-cam which lowers everyone’s Intelligence by a good 50%. However dumb you think the population is overall, lower it by 50% for anything on the internet and you get a pretty good estimate for intelligence online. To make it worse, everyone thinks they’re an expert online as well. Just facts here
the key word there was "constant speed", nerd stuff ---> meaning in a basic physics question to F=ma on the rope and a=Constant the only answer choice is B because the mass on the rope would never change... honestly though I would have missed it overthinking it
"This is looks counter intuitive and would most definitely just trick students no matter how hard they study or how smart they are."
*"This would make a very good multiple choice question!"*
Counterintuitive =/= "trick students no matter how hard they study"
If you're a physics student, using physics equations, you should get the right answer
@@SuperSMT Also (hopefully) anyone with a grade 12 understanding of physics would be able to figure out why the answer is B. In fact I wouldn't be surprised if it was used in some places. You're assuming air resistance and directional force, not gravity or imperfections in weight distribution.
@cqxmrvcoy True, more rope with greater density means more fuckery. The original thing didn't mention a heavy rope tho
I assume it’s more to show they approach the problem with logic, applying principles of physics, than necessarily getting the correct answer.
If you think this is about trickery, I hope you're not a scientist. It's a great question that only tests cognitive skills of the student. As for all the stuff like "heavy rope, rotor wash etc". It is then normal to assume something in your answer or consider multiple scenarios.
I actually thought it was most likely C or E, since I imagined the main rotors wind having having a lot of effect on the wind. I guess E would work if the rope was really wide and there was a weight. Same as C requiring a lot more surface area and downward wind for it to work
Yeah, my prediction for E seems to be something more likely with a flat strap with minimal or no weight beyond the hook or shackle. As the rope is round and sheathed, it isn't affected by airflow as much as I predicted.
Answer D is accurate for ropes with hooks or shackles. I've seen it like that when watching Blackhawks fly away after dropping a cargo load while I was in service.
Being a soldier trained in Air Assault school, this fascinated me very much. :) Thank you for doing this experiment. :)
“Interestingly no one picked e” Derek making me second guess my life
I'm with you buddy
I made a video solution for this problem.
Click for a mathematical explanation 😀👍
@@Candority “Don’t be so needy.”
- C. Montgomery Burns
In fact, I picked E. I was sooooo wrong. LOL
I picked E because I thought it was the most interesting. No regrets.
I love how Derek went out of his way to change the experiment to make us all who voted incorrectly partially correct!
Not if you voted E
I made a video solution for this problem.
Click for a mathematical explanation 😀👍
@@Candority Nice
Haha, I wish he stopped when my B answer was proven right.
@@marcelo55869 Or A. Thankfully I voted D
Always interesting. I never know what you will think up next for a video.
I can't believe you got #1 to pilot that vessel. I couldn't imagine the enterprise without him.
I sat on the toilet when i saw the poll, so i took a roll of toilet paper unrolled it a little, swung it at pretty much constant speed a few times and swiftly switched my answer from C to B 🤷♂️
You're leaving us in suspense about then end, pulling that parachute back up where it gets dangerously close to the rotors. I assume you maybe just dropped the whole rope at that point?
They never came down.
@@ToehsStorage legend says they're still up there
Or they can just make the helicopter hover in mid air, not moving forward or backward, then pull it up while it is hovering. Even if the chute is dangerously close to the rotor, the can manuver the heli backward so the rope curve the other way then pull it up. Regardless it is safe to say, they are alive and well so they did it the right way haha
@@harryvinh6413 he specifically mentioned the whipping action. The wash causes it without forward movement
@@EricLS rope is too heavy to make anything surprising.
Check out some helicopter aerial refueling videos if you like these. The shape of the dangling refueling hose is altered to support engagement with the helicopter. Do they increase weight or air resistance? Take a look!
Kaguya is safe! Probably...
Thank you for answering what conditions were necessary for each rope shape. The fact that three were possible and you went out of your way to model them was amazing, fantastic content as always.
the fact i was so intrigued by the question and was trying my best to figure out the answers to all the questions asked is why i love this channel so much.
What is intriguing about this question is it isn't a physics question at all, it's an aerodynamic question and a rotary wing one to be exact. Helicopters are very similar to planes but also have huge differences that can confuse any other pilot. Individual blades move fore and aft, twist, change angle of attack, and can lead and lag depending on where that blade is in relationship to the swashplate (top of helicopter where all the blades meet). We have transverse flow effect, effective translational life, gyroscopic procession (actions occur 90 degree in the direction of rotation), and all kinds of weird stuff that must have baffled the first helicopter engineers. We can even have air flow backwards through the rotor system if in a descent with specific power applied (can be deadly) if forward airspeed isn't increased before smashing into mother earth. We also have the deadman zone, which during take off, you don't move forward and gain altitude fast enough to get through ELT, and you are too heavy (and stupid), and you lose an engine or transmission, you die. When I saw the pilot in the video do that quick take off and 180 degree turn, I felt nauseous. That is a hotdog or someone who doesn't have military experience to know that is a terrible way to take off. I don't care what direction the wind was or how much power he had, that is a dangerous take off to perform.
LOL I was taking the practice test and searched it up, not expecting Veritasium himself to settle this.