Dope Tech Episode 2

<<@AjDannucci says : I was right !>> <<@jonatosorio says : No. The answer is A: 1. It says the helicopter should be moving to the right. 2. The diagram is shown from the side. 3. This means that even though the cable is angled, the diagram doesn't show the depth; it should appear straight in the side view. 4. From that perspective, the answer could only be B if the helicopter were moving forward.>> <<@maruthasalamoorthiviswanat153 says : ❤ superb>> <<@LucasWalsh-q4i says : I KNEW IT WAS B!!!!!>> <<@alexjo4483 says : All answers are wrong. If it flights to the right the cable should go to the left. Eiter you read it wrong or ther is no right answer>> <<@Prof_Meowington says : Hanging straight and to the left hehehe>> <<@FranzDeRoma says : Negligable 💀>> <<@elielhudson7378 says : I got it right. For civil engineers thats very easy. Its like a cantilever beam, but not fixed at the suport (what would be hypostatical) with a constant load along it. the cable dont flex because its stiffness in the conection region is too small, so less energy is demanded to turn the cable where you are holding it (its support) than in the midle or the other end. Its a mix of bending moment, canitlever... Lets supose the stiffness of the cabe was similar to a wing os a plane, in that direction. If you're strong enough to prevent it from rotating were you are holding, the shape would be C>> <<@DevanshPal-b1t says : if Indian jee papers were answered this way many indians would be alive>> <<@S1LV3RP01NT says : Wouldnt the actual answer depend on what phase offset the cable was experiencing between its angular resonant frequency and the resonant frequency of the helicopters motive force, which is why the ropes tail wags back and forth. Great pilot, kept the harmonic oscillation minimal enough to give them the result they wanted without a load to keep the rope straight. All of the diagram options in the questions are shapes the rope will take at any point in its journey and the word problem is therefore incorrect.>> <<@hichamessadqi2276 says : Could have done it with a drone>> <<@ccelio5468 says : When people think rope they usually don’t think 20 kg mega gym rope. If it were lighter it would be curved since the downdraft of the rotors would be stronger closer to the helicopter.>> <<@stevenhatem8640 says : Can someon explain why its dangerous? Why everyone is talking about air friction?>> <<@drewmur says : What did the test say was the correct answer?>> <<@SythrenoxYT says : Bro, I guessed in start of video it's B because when helicopter is moving forward the rope will go back at in the end and make a shape kind of this (although I'm sure it is the reason but i just guessed it was B because of this)>> <<@denismiles672 says : Why is that?>> <<@setunotes says : Without Air Friction, how helicopter fly?...if no air Friction only for rope , The correct Answer:(A)>> <<@PurpleTuxCat says : supermj767 can find it>> <<@MediOhh says : I WAS RIGHT!!!!>> <<@coolbrotherf127 says : That was my intuition. Since tension is uniform across the rope, the constant force from the side would affect the entire rope evenly and it would rotate around the point where it is held from. The only way the other shapes make sense is if the rope is unevenly pushes by the wind or is unevenly weighted.>> <<@AJ-jc7sl says : Where's inertia ?>> <<@thecow4071 says : But is it perfectly flexible or uniform??>> <<@PraiseShabanji-e4r says : Plot twist all four answers are correct, just under different conditions. B works for normal forward flight, sure. But crank the wind speed up enough and the cable goes horizontal or above. Get a crosswind from the front and suddenly C makes sense. The question is really asking 'which is right given assumptions we didn't fully tell you which is a different question. Physics is only clean when you control every variables.>> <<@christygeorge9938 says : What was the other controversial answer>> <<@matheusgarros4668 says : Simple shear flow velocity profile>> <<@DanyoAsmi says : The length of the rope is very critical to come to a conclusion. If the length of the rope is small then it will form a straight line as seen in the video but there will always be a certain rope length that will form an inverted parabola if it were long enough, where it would lie in the undisturbed air flow from the rotor downwash.>> <<@timothylam2382 says : too bad the anwser key said C💀🥲>> <<@hunglai9851 says : My answer changed from B to E, and somehow I strongly believed E is the correct one, damn>> <<@AnthonyMaw says : Any kid who has ever flown a kite with streamers hanging from it knows this! The airflow impinging on the rope in it's diagonal angle has a vertical lift component that is acting linearly along it's length. The angle of the rope depends on the velocity. The rope is self-lifting so it is logically a straight line but the angle that it hangs down depends on the air speed and consequently the vertical lift component. If the helicopter is going faster the rope will be at a shallower angle.>> <<@tanker9987 says : But that rope is probably far heavier than what was implied in the exam, what would a much lighter rope do? Would the draft from under the helicopter play more of a role?>> <<@rafk2976 says : Well, nice to know I would have got the answer to that in 5 seconds and got on with the exam. I'm surprised this was controversial in any way.>> <<@Voltechs says : I love that I was able to reason through this based on my understanding of physics. Take that AI!>> <<@Beelover-z4d says : It always makes me nervous when i remember helicopters DON'T have doors>> <<@xhyzen888 says : Constant velocity will render acceleration 0, so we can apply Newton’s second law for horizontal motion to be Fdrive-Fdrag = ma, which is Fdrive=Fdrag or basically the only force acting on the rope/helicopter is drag. Which will be the same relative velocity but in a opposite direction which can be modeled with F= kv^2 unless you use the other longer equation but it shouldn’t matter this is a conceptual problem. If you were to take the slope of the drag force it’ll be a straight line horizontally as v is constant and k is also a constant, so no rate of change. It’s a complicated way to explain it, but correct me if I am wrong.>> <<@heirhead123 says : The question was "as the helicopter flies through the air to the right", so none of the options were correct.The test was done flying to the left, which means they didn't answer the question. And since they didn't specify the weight of the rope, all options could be correct, but only when flying to the left with different weight ropes for each test.>> <<@MuzammalHussain-b6e says : I think there may be other possibilities due to weight. The heavier the weight, the more it will curve.>> <<@medmdeux2 says : Mostly (B) But sometimes (E) So both of them should be correct. I'm not saying that because I chose both of them in the beginning 🙂>> <<@DaniellaRodgers-y2z says : Yeah B sounded like the best answer lol>> <<@izzetyl says : But how you made air resistance 0 on rope ?>> <<@brandonb1712 says : I said a when not moving and B when moving>> <<@f2pboii497 says : i would say it would look like hook if the rope was longer and air density function decreased by noticeable amount with increase in height, this experiment felt like inertia was doing all the work and air friction was about the same on every point of the rope, just my opinion idk>> <<@giuseppeugo2716 says : Fast. Clear. Irrefutable. Thank you>> <<@somendrasharma4907 says : Ok. I guessed right... For the first time! B is the answer! 😊>> <<@HanrgyHippopotamus says : The question says nothing about the helicopter going forwards. It is going constantly right, and right only.>> <<@HanrgyHippopotamus says : None perfectly elastic cable>> <<@satori9928 says : What if we consider CORIOLIS FORCES?>> <<@LizziePerson says : “You can clearly see the rope is hanging diagonally and to the left.” And you can clearly see that Derek Muller is hanging on to the heli by a thread 😭>> <<@robertwood9532 says : It was some of me, but it also was forming a droop at the end that appeared over and over again, so it was a bit a D also>> <<@aidanwebster75 says : Assuming air resistance is roughly constant, the deflection of the rope is dependant on the distance from the base and mass being deflected, and since mass increases linearly, the deflection is linear>> <<@b_1729-j8j says : Can someone provide the explanation? I thought the answer is D>>