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!

Surface Integral of quarter-cylinder

  1. Sep 30, 2010 #1
    1. The problem statement, all variables and given/known data
    I am taking the surface integral over a quarter cylinder. Everything is fine and I can get the correct answer, it's just a conceptual problem that I need help with.


    2. Relevant equations

    The da for the "curved" outer surface is [tex]da=sd\phi dz\hat{s}[/tex]
    The da for the bottom surface is [tex]da=sdsd\phi (-\hat{s})[/tex]

    I understand why the curved da is multiplied by s, since we are integrating over a surface that is projected into 3-space by a distance s.

    I do not understand why this s occurs in the da for the bottom (and top) surface. We integrate over a dynamic ds to find the surface integral for this piece....so why multiply the differential area by s?
     
  2. jcsd
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: Surface Integral of quarter-cylinder
Loading...