Lagrangian Mechanics: A pendulum swinging from a moving horizontal cart.

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  • เผยแพร่เมื่อ 14 พ.ย. 2024

ความคิดเห็น • 19

  • @alakis
    @alakis 4 ปีที่แล้ว +5

    I should be studying but here I am, watching random TH-cam videos.

  • @gbpferrao
    @gbpferrao 2 ปีที่แล้ว +2

    I'm a architecture student and i should be doing an essau about the main features of architecture design throughout history, though I am here amazed by lagrangian mechanics

  • @navneetmishra3208
    @navneetmishra3208 4 ปีที่แล้ว +1

    Can u please derive an equation for a ball that is attached with massless string to a circular rod of some radius and the ball is making whirlpool motion around the circular rod if some tangential velocity is given to the ball.
    I am not so good at this kind of questions and in lockdown your videos are helping me a lot. and ur python code is a cherry on a cake.
    perfect!

  • @elir9077
    @elir9077 2 ปีที่แล้ว +1

    Thanks for all the great videos. Is it also possible to do this in polar coordinates?

  • @SpinoStirk
    @SpinoStirk ปีที่แล้ว +1

    When taking the partial of L with respect to θ, should'nt it be (θdot)² instead of (θdot) since you're derivating cosθ ?

  • @imael_8532
    @imael_8532 4 ปีที่แล้ว +2

    Hi, sorry to bother you! Firstly, the video is truly amazing. I loved my university course about Lagrangian mechanics and I've never thought to use programming to create a model of the systems we studied. Let's get to the question: I've never seen a Python program before (in my uni we studied a bit of C++), so I have a question about it. What does the stick.axis part do? I mean, what's the value or variable associated with it? Thank you, sorry for my bad English! :)

    • @DotPhysics
      @DotPhysics  4 ปีที่แล้ว

      stick is the name of the object "stick" - it's an object type cylinder. The axis is a vector from one end to the other - here is the info on cylinders - www.glowscript.org/docs/VPythonDocs/cylinder.html

  • @RickyKwokMath
    @RickyKwokMath 4 ปีที่แล้ว +2

    Amazing. I'm sure you've already thought about this, but what does the Lagrangian look like (and simulation) if you assume the cart is on a frictionless plane so that the frequency (omega) is also time dependent with an initial condition of some theta between 0 and pi/2?

  • @MG-yg3fn
    @MG-yg3fn 2 ปีที่แล้ว +1

    Amazing.

  • @Fouriersoft
    @Fouriersoft 4 ปีที่แล้ว +3

    You mentioned at 1:25 your cart moves back and forth according to time, and not according to the position of the pendulum mass... How does that make sense? If you remove the pendulum, the cart will not oscillate, so surely the carts position is dependent on theta, the relative position of the pendulum mass?

    • @DotPhysics
      @DotPhysics  4 ปีที่แล้ว +4

      It's like a driven cart at the top with a motor. It's motion does not change because of the swinging mass.
      We could make another case with a free car at the top - but that would be a different solution.

    • @Fouriersoft
      @Fouriersoft 4 ปีที่แล้ว

      @@DotPhysics oh I see, I must have missed that part. Thank you

  • @JasonJin3
    @JasonJin3 2 ปีที่แล้ว

    Amazing! Why was kinetic energy of jiggle not considered?

    • @DotPhysics
      @DotPhysics  2 ปีที่แล้ว +1

      there is an external force on the pivot point -since the point moves, the external force does work on the system to change the energy.

  • @Stuk4s
    @Stuk4s 4 ปีที่แล้ว +1

    Super cool

  • @marwasaif1260
    @marwasaif1260 2 ปีที่แล้ว

    Why do we only have one degree of freedom?

    • @DotPhysics
      @DotPhysics  2 ปีที่แล้ว +1

      The position of the cart is set by the oscillation function - it is not free to move however it likes. That leaves just one degree of freedom.
      Don't confuse this with the similar problem that has a cart on a track that's free to move and a pendulum swinging underneath - that would have 2 degrees of freedom (I might already have a video on this version).

  • @science8544
    @science8544 2 ปีที่แล้ว

    why is Y = -Lcos(theta) and not Y = L-Lcos(theta) ?