The Inclined Plane - Derivation using Lagrangian Mechanics!

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  • เผยแพร่เมื่อ 1 ธ.ค. 2019
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    Today we are going to derive the equations of motion for the inclined plane with fixed inclination :) Using lagrangian mechanics is the tool right here and it's going to work absolute wonders! Hangabtriebskraft ahoi, enjoy! =D
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ความคิดเห็น • 147

  • @AndrewDotsonvideos
    @AndrewDotsonvideos 4 ปีที่แล้ว +177

    okay so basically you should do more of these furshur

    • @HandresPovidaiko
      @HandresPovidaiko 4 ปีที่แล้ว +2

      @@PapaFlammy69 Yes pls, moar

    • @matthewcapstick6242
      @matthewcapstick6242 4 ปีที่แล้ว +2

      Andrew... Can you help also congrats with the plaque...
      f(z)=z^3+mz^2+nz-52
      Given that the roots of the cubic equation f(z)=0 are a, 1/a and a+13/a+46 find the roots of the equation f(z)=0

    • @noether9447
      @noether9447 4 ปีที่แล้ว +4

      @@matthewcapstick6242 I think there is a typo in your question. Can you check it again?

    • @owen7185
      @owen7185 3 หลายเดือนก่อน

      Agreed 💯💯💯💯

  • @victorrizkallah6014
    @victorrizkallah6014 4 ปีที่แล้ว +146

    Solve this inclined plane problem again but in curved space time I dare you

  • @duncanw9901
    @duncanw9901 4 ปีที่แล้ว +110

    >makes operator theory videos
    >doesn't want to solve nonlinear DE's

    • @duncanw9901
      @duncanw9901 4 ปีที่แล้ว +4

      @@PapaFlammy69 using Lie-Trotter or smm here might be as much of a nuke as using the Lagrangian. Glad to see the physics content tho, the simple example of the complex method always helps

  • @abdqs853
    @abdqs853 4 ปีที่แล้ว +75

    And here ladies and gentleman we have a man cutting cardboard with a chainsaw

    • @neilgerace355
      @neilgerace355 4 ปีที่แล้ว +4

      It is like asking the robot to bring the two stowaways to the bridge #h2g2

  • @non-inertialobserver946
    @non-inertialobserver946 4 ปีที่แล้ว +190

    That's like using an angle grinder to cut a piece of paper

    • @hoodedR
      @hoodedR 4 ปีที่แล้ว +17

      Or a samurai sword to cut your sandwich

    • @Ricocossa1
      @Ricocossa1 4 ปีที่แล้ว +1

      Pretty much yeah xD

    • @Bloodsaberxy
      @Bloodsaberxy 4 ปีที่แล้ว

      If the paper wasn't there it wouldn't get cut in the first place

    • @generalizedkyle
      @generalizedkyle 4 ปีที่แล้ว +1

      Exactly what Lagrangian mechanics is.

    • @non-inertialobserver946
      @non-inertialobserver946 4 ปีที่แล้ว +4

      @@generalizedkyle Ok but try solving a double pendulum problem without lagrangian

  • @subhasish-m
    @subhasish-m 4 ปีที่แล้ว +41

    6:19 Didn't expect to see one of Grant's pi creatures!

    • @hoodedR
      @hoodedR 4 ปีที่แล้ว

      Xd same

    • @ROBLOXLMaDer
      @ROBLOXLMaDer 4 ปีที่แล้ว

      Subhasish Mukherjee omg hi i also was watching this video

  • @ChariotduNord
    @ChariotduNord 4 ปีที่แล้ว +3

    Lagrangian mechanics is love, Lagrangian mechanics is life.
    Papa, even though the force is downwards, I believe the coordinate y should still be positive r*sin(phi). This would give a U=+mg*r*sin(phi) and you end up with r(t)= -t^2/2 which makes sense because the radius should be decreasing.

  • @MRMarvLPs
    @MRMarvLPs 4 ปีที่แล้ว +31

    For the negative sign to appear in the y-coordinate you have to define your y-axis the other way!

    • @Downloader77
      @Downloader77 4 ปีที่แล้ว +2

      I was looking through the comments to see who else noticed!

    • @hydropage2855
      @hydropage2855 ปีที่แล้ว +5

      Wait wtf your username is Lagrange just noticed lmao

  • @quellodifisica295
    @quellodifisica295 4 ปีที่แล้ว +16

    In order to get the minus sign on the y component you should have chosen the opposite direction for y. If you do that, the potential energy is -mgy (if y=0 is your zero potential energy) and you correctly get that r decreases, as it should.

  • @RC32Smiths01
    @RC32Smiths01 4 ปีที่แล้ว +7

    Lagrangian Mechanics are really fun to do man! Always a pleasure to tune in

    • @RC32Smiths01
      @RC32Smiths01 4 ปีที่แล้ว

      @@PapaFlammy69 Ahh definitely my man!

  • @MrBenten867
    @MrBenten867 4 ปีที่แล้ว +13

    When u use the infinity stones to order a pizza

  • @tuomio5043
    @tuomio5043 4 ปีที่แล้ว +4

    You just combined all my freshman year engineering classes.

  • @49fa75
    @49fa75 4 ปีที่แล้ว +23

    >mfw dotson and papa upload at the same time

  • @JaybeePenaflor
    @JaybeePenaflor 4 ปีที่แล้ว +31

    Just goes to show how mathematics is the language of science and how physics is the purest of all the applied sciences.

    • @henryhung2795
      @henryhung2795 4 ปีที่แล้ว +3

      *Angry biologists scream in the corner*
      DNA methylation rate is basically the only thing, ever

  • @mikhailmikhailov8781
    @mikhailmikhailov8781 4 ปีที่แล้ว +26

    Tfw you nuke a fly.

  • @joaomongesoria2762
    @joaomongesoria2762 2 ปีที่แล้ว

    thanks, really I appreaciate because in most books and classes only the newton approach of that problem is used. I learn something new

  • @FGj-xj7rd
    @FGj-xj7rd 4 ปีที่แล้ว +1

    Thanks man. Been waiting for quite a while for this thing.
    By the way, papa Newton is proud for using his dots.

  • @michaelzumpano7318
    @michaelzumpano7318 4 ปีที่แล้ว

    I love Lagrangian mechanics. Beautifully done! You work so hard to bring us die vergnugung. I’m gonna buy some of your merch.

  • @MrRyanroberson1
    @MrRyanroberson1 4 ปีที่แล้ว +12

    idea: calculate force on an inclined plane *relativistically*

    • @zoltankurti
      @zoltankurti 4 ปีที่แล้ว +4

      Doesn't work: newtonian gravity leads to contradictions in special relativity, and in general relativity you would get a nonlinear differential equation (the geodetic equation with constraints), and as flammy said in this video, he doesn't like those.

  • @owen7185
    @owen7185 3 หลายเดือนก่อน

    Please don’t stop these lectures

  • @wilhelmsarosen4735
    @wilhelmsarosen4735 4 ปีที่แล้ว +3

    Papa and Dotson in harmony with each other!

  • @Mayank-mf7xr
    @Mayank-mf7xr 4 ปีที่แล้ว

    coolest physics channel on youtube imo.

  • @eva-jd2zg
    @eva-jd2zg 4 ปีที่แล้ว +2

    That feeling when you're at work and can only comment and like and not watch the video until tonight. HAPPY SECOND DAY OF ADVENT! #fpadventcalendar

    • @eva-jd2zg
      @eva-jd2zg 4 ปีที่แล้ว

      @@PapaFlammy69 Hiyaaaa \o/ Got to watch the video last night while working more (and eating ice cream WOOOO!) but didn't get to follow along too closely so hopefully I can get my hanabtriebskraft on today and pull out that notebook XD Looking forward to day 3! #pfadventcalendar

  • @bowiebrewster6266
    @bowiebrewster6266 4 ปีที่แล้ว

    This is the first time ever i knew exactly what u were going to do in a vid

  • @victorrizkallah6014
    @victorrizkallah6014 4 ปีที่แล้ว +33

    How dare you make a physics video after making fun of Richard feynman. I'm still waiting for you to apologize to feynman. HAIL RICHARD FEYNMAN. Good video tho

  • @zacharyjasper6367
    @zacharyjasper6367 4 ปีที่แล้ว

    Idk if one is specifically supposed to look for polar coordinates, but great video all around! Thank you!

  • @sverrehestholm723
    @sverrehestholm723 4 ปีที่แล้ว +1

    Love the physics content!

  • @federicopagano6590
    @federicopagano6590 3 ปีที่แล้ว

    According to the ssystem x =-r cos and y=r sin , if we define x=r cos y=-r sin clearly the particle velocity will point upwards, the particle will climb upwards (dr/Dt < 0 )

  • @shanee4497
    @shanee4497 4 ปีที่แล้ว +3

    Ah finally, some flammy mechanics

  • @papalaplace
    @papalaplace 4 ปีที่แล้ว +6

    Seems like Papa has made a deal with the devil to get brilliant at math, but now he can't use Newton's second law.

  • @MasterStroke.
    @MasterStroke. 4 ปีที่แล้ว

    Two pendulums of masses m1 and m2 and lengths l1 and l2 hang from the ends of a bar with no weight of length 2L, which is suspended in its center O. Both the pendulums and the bar can rotate freely around the suspension points: P1, P2 and O. Assuming that all the movements are carried out in the vertical plane, analyze the constraints and determine the degrees of freedom of the system.

  • @egillandersson1780
    @egillandersson1780 4 ปีที่แล้ว

    You are a really mad scientist ! 😉🤣😂
    Thank you for that.

  • @danielsuarezlopes4004
    @danielsuarezlopes4004 4 ปีที่แล้ว

    Verry good! 👊

  • @technoguyx
    @technoguyx 4 ปีที่แล้ว +1

    A German boi pronouncing *L A W H U U N J* perfectly, who could've thought. Cool video btw, I'm a math major secretly wishing to take Analytical Mechanics next year but also sort of scared.

  • @danielsuarezlopes4004
    @danielsuarezlopes4004 4 ปีที่แล้ว

    Ótimo vídeo. 😎👨‍🏫

  • @NovaWarrior77
    @NovaWarrior77 4 ปีที่แล้ว +1

    OMG I never knew you were kind of a physics boi!

  • @cameronspalding9792
    @cameronspalding9792 4 ปีที่แล้ว +2

    I would have chosen coordinates u and v where v measured the distance from the plane (which stays a constant zero), whilst v measures the distance falls along the plane

  • @ShaderKite
    @ShaderKite 4 ปีที่แล้ว

    Nice finally some physics :D

  • @neilgerace355
    @neilgerace355 4 ปีที่แล้ว +3

    1:57 Close Lagrange Encounter of the Second Kind

  • @avicennam7708
    @avicennam7708 4 ปีที่แล้ว

    Great video

  • @hakongray
    @hakongray 4 ปีที่แล้ว

    Fuck yes! More of this papa flammable

  • @tszhanglau5747
    @tszhanglau5747 4 ปีที่แล้ว

    "this mess right here" yeah
    Papa Laplace would be proud

  • @MasterStroke.
    @MasterStroke. 4 ปีที่แล้ว

    A particle of mass m slides under its own weight and without friction on the inner surface of an inverted vertical cone of semi-angle α. Use the Lagrange multiplier method to find the constriction force. Express your result in terms of the energy and the z component of the particle velocity.

  • @pythagorasaurusrex9853
    @pythagorasaurusrex9853 4 ปีที่แล้ว +5

    I just wonder, if you intentionally pronounciate "mass" as "mess" (ca. 2:00). Yes, physics and math can become a mess :) Love your brute-force derivation!

  • @MasterStroke.
    @MasterStroke. 4 ปีที่แล้ว

    A body of mass m slides without friction on an inclined plane that forms an angle θ with the floor of an elevator. If the lift goes up with uniform acceleration α:
    a) Describe the inertial system.
    b) The natural coordinates and,
    c) Explicitly describe the holonomic constriction on the body.

  • @MasterStroke.
    @MasterStroke. 4 ปีที่แล้ว

    Two masses m1 and m2 are suspended from a rope of length l1 that passes over a pulley. Two other masses m3 and m4 are simultaneously suspended by a rope of length l2 that passes over another pulley. These two pulleys hang from the ends of a rope of length L that passes over a third fixed pulley. Write down the constraints explicitly and determine the degrees of freedom of the system.

  • @douglasstrother6584
    @douglasstrother6584 4 ปีที่แล้ว

    Papa Flammy goes all "Least Action" on us!
    WHOOT!!

    • @douglasstrother6584
      @douglasstrother6584 4 ปีที่แล้ว

      I can't wait for the Quantum Mechanical version!

  • @hehebwoai3056
    @hehebwoai3056 4 ปีที่แล้ว +7

    Can we have a series on some 🆎️stract stuff + flying 🆎️ creatures (mohamed's profile pic)

  • @Polaris_Babylon
    @Polaris_Babylon 4 ปีที่แล้ว +5

    Physics yay

  • @ozzymandius666
    @ozzymandius666 4 ปีที่แล้ว +2

    Here's a tough one for ya, Flammy: Does there exist a curvature of the plane k such that neither k nor the circumference of a unit circle on said plane are transcendental?

  • @EmissaryOfSmeagol
    @EmissaryOfSmeagol 4 ปีที่แล้ว +2

    I appreciate physics content.
    TBH Langrangian Mechanics was the easiest part of Classical Mech. for me, since it's just solving a DE. The rest of CM was pretty hard!

  • @tabrez3179
    @tabrez3179 4 ปีที่แล้ว +2

    yes some mechanics!

  • @jaikumar848
    @jaikumar848 4 ปีที่แล้ว +1

    Could you please make video on orbital mechanics?

  • @charleswilson7458
    @charleswilson7458 4 ปีที่แล้ว +1

    More physics videos please!

  • @youssefderrazi6246
    @youssefderrazi6246 3 ปีที่แล้ว

    I'M STILL GETTING THESE RECOMMENDED

  • @J.P.Nery.N.
    @J.P.Nery.N. 4 ปีที่แล้ว

    Yay some physics again! Please do more papa, love u bruh (no homo)

  • @brunoynobruno
    @brunoynobruno 4 ปีที่แล้ว +1

    You have forgotten include de force due to friction as a generalized force in the motion ecuation.

  • @Paul-ob2hy
    @Paul-ob2hy 4 ปีที่แล้ว

    please do more mechanics !!

  • @lordstevenson9619
    @lordstevenson9619 3 ปีที่แล้ว

    Oh flammy it was almost perfect, 5:18. 😂

  • @nick_ca
    @nick_ca 4 ปีที่แล้ว

    Hey I have a final in this sort of thing on Monday can you maybe cover all of Lagrange's and Hamilton's equations next time?

  • @JacoTheDeadRuler
    @JacoTheDeadRuler 4 ปีที่แล้ว +1

    I learned a little bit of LaTeX last night for honors homework. {/bf :D} = *:D*

  • @planetsharks4746
    @planetsharks4746 4 ปีที่แล้ว

    I love you

  • @strengthman600
    @strengthman600 4 ปีที่แล้ว

    Papa can you do some spicier systems in lagrangian mechanics thanks ly

  • @matron9936
    @matron9936 4 ปีที่แล้ว +3

    Wer kennt schon HANGABTRIEBSKRAFT nicht?

  • @nuklearboysymbiote
    @nuklearboysymbiote 4 ปีที่แล้ว +1

    i bought some more flammable merch :3

    • @nuklearboysymbiote
      @nuklearboysymbiote 4 ปีที่แล้ว

      @@PapaFlammy69 cant wait for it to arrive eeee

  • @ozzymandius666
    @ozzymandius666 4 ปีที่แล้ว +1

    Lagrange and Hamilton walk into a bar...later they leave at 1.41421...the speed they walked in at, because they are now both broke.

  • @zoltankurti
    @zoltankurti 4 ปีที่แล้ว

    L=g_{kl}*x'^k*x'^l
    g_{kl} are functions of the coordinates, and g_{kl}=g_{lk}. x'^k is the derivative of the kth coordinate with respect to some arbitrary parameter, and there is automatic summation for k and l (lets say we are in a 4 dimensional space, so summation from 0 to 3). Calcukate this one, and you obtain the geodesic equation, which would describe a free falling point particle in general relativity. You could make a video out of this.

  • @damienvoid7762
    @damienvoid7762 4 ปีที่แล้ว

    I just watched papa flammy set the house on fire to cook a instant ramen.

  • @owen7185
    @owen7185 3 หลายเดือนก่อน

    This shit is amazing

  • @thedoublehelix5661
    @thedoublehelix5661 4 ปีที่แล้ว

    Calculus of Varations for an inclined plane? Noice

  • @Lklibertad
    @Lklibertad 4 ปีที่แล้ว

    bazooka to kill a fly

  • @Ottmar555
    @Ottmar555 4 ปีที่แล้ว

    Pappa Flammy, I'm having trouble with a complex integral to find the solution of a PDE using Laplace transform. Would you like to help me and publish our findings together?

  • @bamdadtorabi2924
    @bamdadtorabi2924 4 ปีที่แล้ว

    Hey Jens! I wanna send you an Integral. where should I send it for you?

  • @violymhi
    @violymhi 4 ปีที่แล้ว +1

    Seriously? My analytical mechanics midterm was litteraly 6 hours ago, why oh why didn't you post this yesterday?

    • @violymhi
      @violymhi 4 ปีที่แล้ว

      @@PapaFlammy69 I forgive you😋

  • @nnniv
    @nnniv 4 ปีที่แล้ว +2

    one lagrangian boi

  • @nareshmehndiratta
    @nareshmehndiratta 2 ปีที่แล้ว

    please remake Feynman lectures in physics

  • @davialefe7646
    @davialefe7646 4 ปีที่แล้ว

    Shit I was looking for that like a couple days ago and couldnt find much. Is this on demand service papa?

    • @davialefe7646
      @davialefe7646 4 ปีที่แล้ว

      Btw you know that shirt implies sinx=x right?

  • @matthewcapstick6242
    @matthewcapstick6242 4 ปีที่แล้ว +1

    Can anyone help...
    f(z)=z^3+mz^2+nz-52
    Given that the roots of the cubic equation f(z)=0 are a, 1/a and a+13/a+46 find the roots of the equation f(z)=0

  • @allaincumming6313
    @allaincumming6313 4 ปีที่แล้ว

    Now do it with a perfect circle rolling down xd.

  • @gian2kk
    @gian2kk 4 ปีที่แล้ว

    Ciao :D

  • @robertsteinbeiss8478
    @robertsteinbeiss8478 4 ปีที่แล้ว

    it is a mass not a mess, ..... but if a mathematician does physics that is what you get! 🤣 Let's solve the spherical chicken in a vacuum!
    Sry that was a cheap joke! Actually I love the simplisity of this basic concept that cover many questions in GR and is jet somehow connected to the Hamiltonian Formalism that works in the quantum world. There is more to it than the math!

  • @OmegaBlackjack
    @OmegaBlackjack 4 ปีที่แล้ว

    0:26 Is it a JOJO REFERENCE BOIIII?!

  • @seetj12
    @seetj12 4 ปีที่แล้ว

    Solve double pendulum with F=ma

  • @lezhilo772
    @lezhilo772 4 ปีที่แล้ว

    Now work out the two-body problem where the incline itself has mass M and can move!

  • @MaarioneteSR
    @MaarioneteSR 4 ปีที่แล้ว

    that's gonna be a bill gates with a giant paddle and small ping pong ball from me.

  • @pjmmccann
    @pjmmccann 4 ปีที่แล้ว

    So, in short, if you note that the effective acceleration a is g*sin(phi) (the component of gravity "down" the incline) then the solution to Newton's equation is (wait for it!) s(t) = s(0) + v(0)*t + a*t^2. WHODATHUNKIT?

  • @beevees1636
    @beevees1636 4 ปีที่แล้ว

    Man, you're just shooting a mosquito with a cannon

  • @rorincampbell7894
    @rorincampbell7894 4 ปีที่แล้ว +1

    “If we remember correctly from 3rd grade physics > T=m/2r^2” ahhh of course.... 3rd grade physics

  • @truthmatters5536
    @truthmatters5536 4 ปีที่แล้ว

    OK, smart boy, I modify the problem slightly to make it harder to solve. Suppose the slope is given by a triangle block that is sitting on the smooth surface and it moves freely. What will happen to the acceleration of the mass, m, placed on such a triangle block? Assume the triangle block mass is capital M. That is MIT level.

  • @Patryk947f
    @Patryk947f 4 ปีที่แล้ว

    You should have told g = -pi^2 because otherwise the mass would be moving uphill.

  • @ShadowTB-ds4ks
    @ShadowTB-ds4ks 4 ปีที่แล้ว

    That's like killing a mosquito with a bazooka

  • @annakquinn7084
    @annakquinn7084 2 ปีที่แล้ว

    On your integral you forgot the double dot r.

  • @jasonforbus8605
    @jasonforbus8605 4 ปีที่แล้ว +1

    he says Lagrange like how la croix looks like it’s pronounced

  • @Bloodsaberxy
    @Bloodsaberxy 4 ปีที่แล้ว

    The kind of things you read to your kids before sleep

  • @nanigopalsaha2408
    @nanigopalsaha2408 4 ปีที่แล้ว

    3b1b_oid

  • @ivancheems35
    @ivancheems35 4 ปีที่แล้ว

    Phi=theta? :0

  • @einsteingonzalez4336
    @einsteingonzalez4336 4 ปีที่แล้ว

    In 0:19 - 0:20, what is that phrase?

  • @doggmasta6452
    @doggmasta6452 4 ปีที่แล้ว

    you made a mistake i think because de potential is mgsin(phi) actualy and the you get r(t) = - sin(phi)*t^2 + ... as it would be expected to go to a smaller radius héhé

  • @Mot-dh5sx
    @Mot-dh5sx 4 ปีที่แล้ว

    That’s cool and all, but did you know F = ma? hA

    • @Mot-dh5sx
      @Mot-dh5sx 4 ปีที่แล้ว

      @@PapaFlammy69 :'3