1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Fourier sine series for a triangular wave on a finite string

  1. Mar 22, 2016 #1
    1. The problem statement, all variables and given/known data
    A string of length L =8 is fixed at both ends. It is given a small triangular displacement and released from rest at t=0. Find out Fourier coefficient Bn.

    2. Relevant equations

    what should i use for U0(x) ?
    3. The attempt at a solution
    fourier sin.png
     
  2. jcsd
  3. Mar 22, 2016 #2

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hello nazmus, :welcome:

    ax from 0 to L/2 and x(1-x) from L/2 to L . Oops :nb), I'm not supposed/allowed to give direct answers !
     
  4. Mar 22, 2016 #3

    LCKurtz

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    First, you need to know what the "small" displacement is. Let's say you lift the center by an amount ##h##, so the center of the string is at ##(\frac L 2,h)##. Now just find the equation of the two straight line segments forming the triangular displacement. Also, I would ignore BvU's answer which is a) discontinuous and b) partially parabolic.
     
  5. Mar 22, 2016 #4

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    No, it was just a typo. I (of course) meant

    ax from 0 to L/2 and a(L-x) from L/2 to L
    And for the Fourier coefficient calculation it really doesn't matter how big a (or h) is.

    All lin good spirit :smile:

    Cheap, fast, and reliable. Pick any two
    .
     
    Last edited: Mar 22, 2016
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Fourier sine series for a triangular wave on a finite string
  1. Fourier Sine Series (Replies: 2)

  2. Fourier sine series (Replies: 30)

Loading...