Deriving Unit Vectors in Spherical Coordinates (Physics Majors)

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  • čas přidán 28. 08. 2024
  • Second video in a series of derivation videos leading up to the laplacian in spherical coordinates!

Komentáře • 112

  • @paulboard8221
    @paulboard8221 Před 6 lety +108

    Watching this instead of studying for calc is the best decision I've made in my academic career

  • @CossZt6
    @CossZt6 Před 5 lety +36

    Trigonometric cancellations are among the most satisfying things to watch.

  • @AndrewDotsonvideos
    @AndrewDotsonvideos  Před 5 lety +9

    at 11:30, where all of the unit vectors are in a box, the e_phi term should have a minus sign in front of the sin term. The derivation of the unit vector was completely correct, just when I re-wrote the expression I missed a sign. Sorry about that

  • @biologicalpenguin4523
    @biologicalpenguin4523 Před 5 lety +59

    Such a beautiful explanation - exactly what i was looking for!

  • @dodgeking2293
    @dodgeking2293 Před rokem +4

    As an engineering student of electronics major I was looking for this derivation in many sources but they don't exactly explain about derivations of unit vectors. So glad that I now know how to derive it. Thank you ❤

  • @deivanivan_c
    @deivanivan_c Před 5 lety +10

    your handwriting is actually satisfying

  • @anchitasharma4821
    @anchitasharma4821 Před 3 lety +3

    This video deserves soooo many more likes. I saw like 5 videos before this and couldn't understand a thing...but this man made it all easy. Thank u thank u ^^

  • @eccesignumrex4482
    @eccesignumrex4482 Před 5 lety +23

    You left out a minus sign in the x-hat term, for the e(phi) vector at the end of the video - ... otherwise :) ... GREAT video!

  • @KMKPhysics3
    @KMKPhysics3 Před 6 lety +15

    For our first class this week, our professor emailed us to review spherical coordinates in advance, so I just watched all your Spherical Coordinates derivations as my review. Thanks for the clear and to the point derivations!

    • @kayrstar8965
      @kayrstar8965 Před 4 lety +1

      now I am in your place,our professor emailed us to review spherical coordinates in advance, so I just watched all Andrew's Spherical Coordinates derivations as my review

  • @TheSudouser
    @TheSudouser Před 2 lety +2

    Hi Andrew, I am currently a non traditional physics student attending mechanics and I found this extremely useful. I think my Mechanics book 7th edition Fowler and Cassidy is normally up to par with reviewing calc 3 stuff but I was struggling to remember how systems move vectorially in a sphere. This derivation made much more sense to me. I was literally spinning my wheels trying to visualize it. Thanks so much!

  • @chasr1843
    @chasr1843 Před 3 lety +2

    These spherical coordinate vids are really good.🙂. Everybody needs to go through this stuff and this demonstration is nice and complete, and at a reasonable pace. As a teacher I am learning a lot about how to explain things.

  • @keshavthakur3848
    @keshavthakur3848 Před 4 lety +1

    Watched more than 10 videos but got here what I was looking for

  • @lilierguera660
    @lilierguera660 Před 3 lety +2

    Thank you sooo muuuch, you saved my semester, I love youuu 💕

  • @semiawesomatic6064
    @semiawesomatic6064 Před 6 lety +2

    I do t really know what a laplacian is, but the rest of these have made sense so far. It took me a second to get what you were doing at some points, but I guess that's because I've only been through two physics courses and am only about to take my first multivariable calc class.

  • @rozhinmkian6325
    @rozhinmkian6325 Před 5 lety +3

    Thanks for your great explanations!! I'm all set to do my 'scary' homeworks which now don't look that scary!!

  • @ianwinkler7872
    @ianwinkler7872 Před rokem

    Thank you so much for this explanation. I have to derive the toroidal coordinates for a homework assignment and this process is really helping me along.

  • @neelarghosen9827
    @neelarghosen9827 Před 9 měsíci +2

    Awesome video with great explanation...
    just a small correction
    At 11:29 e_hat sub phi will be [- sin(phi) x_hat + cos(phi) y_hat]

    • @sohambSSS836
      @sohambSSS836 Před 9 měsíci

      Yes yes......anyways very nice video....cleared my concept

  •  Před 3 lety

    Watched more than 5 videos but got here what I was looking for

  • @46pi26
    @46pi26 Před 6 lety +16

    11:01
    "That's not what e's look like"
    Me when going through my old math sheets and not being able to tell what's "e" and what's theta

    • @drover7476
      @drover7476 Před 3 lety

      he says things look like hahaha so funny

  • @Bearman5
    @Bearman5 Před 5 lety +2

    Andrew's reaction at 10:38 is priceless! I love that xD

  • @dibyendulalmoitra7402
    @dibyendulalmoitra7402 Před 5 lety +2

    Thank you so much sir it is really helpful.
    From India

  • @kashyapbrahmandam6991
    @kashyapbrahmandam6991 Před 4 lety +1

    Beautiful presentation...love it man

  • @danim5222
    @danim5222 Před 4 lety +1

    Just what I was looking for! Getting that degree one unit vector at a time :D

  • @fluffyzozo1629
    @fluffyzozo1629 Před rokem

    thank god you're not my teacher i wouldn't be able to focus I would just be lost in your beautiful eyes!
    other than that great video thank you!!

  • @hheg2727
    @hheg2727 Před 6 lety +7

    In the summary at the end you forgot a minus at the e_phi vector

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  Před 5 lety +5

      You're right, the derivation was correct though. Just re-writing it I missed the sign!

  • @anshulyadav9619
    @anshulyadav9619 Před 5 lety

    Very helpful derivation was looking for it everywhere but found here only. thanx

  • @lidor394
    @lidor394 Před 5 lety +1

    Thank you for simplifying this so much.

  • @ayursheedey8186
    @ayursheedey8186 Před 5 lety +1

    Andrew,this video was quite helpful and if possible do make a video on Non Inertial Systems

  • @kavitaraghuwanshi2106
    @kavitaraghuwanshi2106 Před 3 lety

    Some people make physics critical but some like u make it so dam simple as that, as it is

  • @lad4694
    @lad4694 Před 4 lety

    Whoop! I've finally started multivariate calc and have the need for this. 🤤🤤I'm so excited

  • @jean-philippesuter2550

    Great video, but with one omission: During the calculation of the magnitude of the e vectors for phi and theta, you don't explain why there aren't any cross terms when squaring the trinomial before taking the square root. I believe the reason is that one doesn't exactly square the trinomial before taking the square root, but rather one takes the dot product of the trinomial with itself, before taking the square root. The dot product elimintes the cross terms, since the unit vectors are mutually orthogonal. Of course, this also explains what happens to, say, x-hat: The dot product of any unit vector with itself is exactly one, so it disappears.

  • @Ab-ub2ii
    @Ab-ub2ii Před 5 lety +1

    this guy is just 'purrfect'

  • @lancelovecraft5913
    @lancelovecraft5913 Před 5 lety +4

    Wowwww so my whole life I've been deriving these geometrically (vector projections and the like) who knew there was an easier way lol I'm dead

  • @indudubey731
    @indudubey731 Před 3 lety +1

    It was really nice explanation 😊😊love it!!!

  • @departmentofphysicsastroph6977

    Very good vedio in which topic nicely explained.

  • @janedicocco5848
    @janedicocco5848 Před 9 měsíci

    Your final statement for the conversion for theta hat to cartesian, in the coefficient of y hat, has sin (phi)cos(phi),
    but should read sin(phi)cos(theta) , as you derived in the video.

  • @Rakeshkumar30
    @Rakeshkumar30 Před 4 lety

    vey helpful...you have done a brilliant job!

  • @Neetusingh-wn3fx
    @Neetusingh-wn3fx Před 4 lety

    Thanks for helping. Love from India

  • @MathPhysicsFunwithGus
    @MathPhysicsFunwithGus Před 3 lety +1

    Great explanation thank you!!

  • @user-vg8ql6wq5v
    @user-vg8ql6wq5v Před 8 měsíci

    I think this video is good. But there is a minor mistake in here, which is about the er and er hat. You didn't clarify whether er is a vector or a "unit vector". Things just went suddenly from er to er hat. Hope you can clarify that!

  • @suf6716
    @suf6716 Před 4 lety +3

    i guess last clip missed the minus sign with "sin" for e of phi

  • @kushalv8268
    @kushalv8268 Před 5 lety

    Excellent video on spherical coordinates thankqq sir

  • @FineFlu
    @FineFlu Před 5 lety +1

    LINK TO OLD VID

  • @tarunramkanuri3581
    @tarunramkanuri3581 Před 6 lety +4

    I don't know about Laplacian. Can I follow this course or should I learn laplacian first and then watch these videos. Until now, it is okay. Should I learn laplacian for next videos.
    Or
    Are you going to teach it in the future videos?

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  Před 6 lety +1

      I'm building up a library of derivation videos that will provide the tools to derive the laplacian. Some knowledge of multivariable calculus would be helpful though.

    • @tarunramkanuri3581
      @tarunramkanuri3581 Před 6 lety +2

      Andrew Dotson , aye, aye, captain. Good at it. Let's go...

  • @CSNidhiSoni
    @CSNidhiSoni Před rokem

    Yeah
    Great Sir
    Thanks a lot

  • @alejrandom6592
    @alejrandom6592 Před rokem

    Thanks so much for this! Btw I think you missed a sign at 11:25

  • @lordyabo9910
    @lordyabo9910 Před rokem

    loved the video! but why does the r unit vector requires only one step to get, and the other two (theta and phi unit vectors) requires two step? Thanks in advance!

  • @0770630116prince
    @0770630116prince Před 5 lety

    you are a god u saved me thank u

  • @azmaeenadib3821
    @azmaeenadib3821 Před rokem

    how did the partial derivative come in and how did you define e,sub,u. i don't get that part

  • @Jordan-s1l
    @Jordan-s1l Před 2 lety

    How do you derive the cartesian unit vectors in terms of the spherical coordinates? I know you can just take the inverse of the transformation matrix, but is there another way? Pls help.

  • @tszyulo6423
    @tszyulo6423 Před 4 lety

    You save me a LOT!

  • @berkelium5534
    @berkelium5534 Před rokem

    at 11:25 y-hat component of e(theta) should be cos(theta)sin(phi). and x-hat component of e(phi) should be -sin(phi)

  • @systempatcher
    @systempatcher Před 5 lety +2

    Your final solution at 11:30 is slightly wrong. The î term for the phi unit vector should be negative. Otherwise great derivation! I'm using yours instead of my books because it is so much more elegant.

  • @ayushilamba651
    @ayushilamba651 Před 4 lety

    Thanks for this video! ❤️

  • @veereshkammara9139
    @veereshkammara9139 Před rokem

    Great work man it helped a lot thanks

  • @henrytay1706
    @henrytay1706 Před rokem

    Extremely helpful!

  • @greywolf892
    @greywolf892 Před 3 lety

    This was very helpful, thank you

  • @vallesprincessc.6645
    @vallesprincessc.6645 Před 2 lety

    Thank you! Ily

  • @the1skinsfan1
    @the1skinsfan1 Před 4 lety

    Awesome video

  • @stevenhernandez3828
    @stevenhernandez3828 Před 2 lety

    Beautiful

  • @46pi26
    @46pi26 Před 6 lety +1

    Have you ever derived the Laplacian using Cauchy Riemann conditions? It's really fun if you haven't done it yet.

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  Před 6 lety +1

      Can't say that I have!

    • @46pi26
      @46pi26 Před 6 lety

      Andrew Dotson Well, if you want to try it out, you just have to get the Cauchy Riemann conditions in polar form, take some second derivatives equating to zero, switch to the z-rho plane, and then it's pretty straightforward from there! I'll be putting out a video on it soon, if you want to check it out!

    • @46pi26
      @46pi26 Před 6 lety

      Andrew Dotson It's been uploaded! Here's a link if you want to check it out!
      m.czcams.com/video/_TXtj2TOnBU/video.html

  • @divyanshsingh4512
    @divyanshsingh4512 Před 3 lety

    good explanation bro..it helped a lot

  • @davidestabrook954
    @davidestabrook954 Před 3 lety

    At about 5:00, what happened to r-hat when finding the derivative? I am not quite following how you just ignored it. Thanks

  • @benceszabo5515
    @benceszabo5515 Před 3 lety

    at 11:30 shouldn't there be a minus sign before sin(theta)X ?

  • @ronaldon.a.1698
    @ronaldon.a.1698 Před 5 lety

    And how can i change the unitary cartesian vectors in function of unitary spherical vectors?

  • @umaoio312
    @umaoio312 Před 6 lety +2

    I'm not gonna say I was anticipating this upload
    But I did check for it on my lunch break
    (no I don't have a job I just call it that because in school that's what it for me - a break. In which I normally don't even eat lunch anyway 🤔)

  • @miasix7147
    @miasix7147 Před 4 lety

    Great video!! But let me take a nap first... I’ll continue later.

  • @priteshsrivastava5850
    @priteshsrivastava5850 Před 3 lety

    At 4:00 , the expression we get for er(hat) and er in terms of x(hat) , y(hat)... are actually coming same ! Why is it so ?

  • @ramk1985
    @ramk1985 Před 5 lety +5

    iam sad because this shows me how much iam suck at physics

  • @jerelfontenot1
    @jerelfontenot1 Před 5 lety

    what about derivatives of unit vectors in different coordinate systems?

  • @haifaalmamari3670
    @haifaalmamari3670 Před 4 lety

    Thank you indeed

  • @sarahkimani8063
    @sarahkimani8063 Před 2 lety

    The hot tr kinda contributed to my understanding 😅😅

  • @raunakashgulati6143
    @raunakashgulati6143 Před 5 lety

    thanks for the help dude!!!!

  • @palurumanoj7401
    @palurumanoj7401 Před 6 lety

    Bro, how could it be said that vector along direction of θ is the partial derivative of vector r with respect to θ?

  • @vvsdhandu
    @vvsdhandu Před 5 lety

    Thanks a ton mate!

  • @user-yq6xs2fz3e
    @user-yq6xs2fz3e Před 3 lety

    Y piece of the theta should be cos 0 sin phi.

  • @mohammedumarsheriff5801

    Link the previous video.do you assist with project work.

  • @varungupta5264
    @varungupta5264 Před 2 lety

    Good video

  • @neox5539
    @neox5539 Před 5 lety +2

    That white board is triggering my ocd.

  • @justadreamerforgood69
    @justadreamerforgood69 Před 4 lety

    2:36
    Where did this step come from ?

  • @shivanshsrivastava9264

    gratly expplained

  • @michaelsowter4438
    @michaelsowter4438 Před 5 lety

    THANK YOU

  • @dansdendanable
    @dansdendanable Před 4 lety

    Nice! I want such a nice board (;

  • @kimothefungenuis
    @kimothefungenuis Před 2 lety

    Still useful for engineering

  • @jacobvandijk6525
    @jacobvandijk6525 Před 5 lety +2

    Thanks, mate! But you made only ONE MISTAKE. After 11:25: the middle term of e-theta must be cos(theta; NOT phi).sin(phi).y. Just compare it with your result after 7:23. Someone has to do the dirty job of verifying things on CZcams ;-)

  • @Asim2846
    @Asim2846 Před 4 lety +1

    plz , Dr. Can you clean your board man!

  • @gyanprakash6241
    @gyanprakash6241 Před 4 lety +2

    100k🙂

  • @sahandehteshami7404
    @sahandehteshami7404 Před rokem

    Im doing engineering and i watched this video for my exam (illegal)

  • @alvinah830
    @alvinah830 Před 2 lety

    Can I take your photo

  • @ambrishabhijatya7842
    @ambrishabhijatya7842 Před 6 lety

    You messed up the "e sub theta hat" and "e sub phi hat" at the very end of the video.

  • @jonsnow3960
    @jonsnow3960 Před 3 lety

  • @mahimasri1271
    @mahimasri1271 Před 6 lety

    Plz make vedio about four vecter

  • @alixdesaint-exupery808

    jtm

  • @BigMoneyPauper
    @BigMoneyPauper Před 3 lety

    ur whiteboard is grody asf sun. good vid tho

  • @robertv4076
    @robertv4076 Před 2 lety

    Clean your whiteboard please!

  • @Upgradezz
    @Upgradezz Před 5 lety

    Thanks bro, but your hair scares me as if it has been troubled by the sheer complexity of your derivation.

  • @JunaidKhan-bp6wc
    @JunaidKhan-bp6wc Před 5 lety

    stupid way