1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Spherical Coordinates

  1. Mar 8, 2009 #1
    The problem statement, all variables and given/known data
    The outermost integral is:
    -2 to 2, dx

    The middle integral is:
    -sqrt(4-x^2) to sqrt(4-x^2), dy

    The inner most integral is:
    x^+y^2 to 4, dz

    The attempt at a solution

    Drawing the dydx in a simple 2d (xy) plane, it is circular with a radius of 2. So this means that the period(theta) will go from 0 to 2pi. Drawing in 3d (xyz) yields a hemisphere/paraboloid. Now this is where I'm stuck. I don't know what to do after this or how to really tackle this problem. Do I want to attempt to draw a 'slice' of it in the spherical outline with the variables phi, rho, theta? Do I have to look at it a certain way (2d or 3d)? I just don't see what I can do!

    Any help or guidance is greatly appreciated!!
  2. jcsd
  3. Mar 8, 2009 #2


    User Avatar
    Homework Helper
    Gold Member

    You haven't actually said what the question asks you to do..
  4. Mar 8, 2009 #3
    Whoops. Thought I stuck that in there. Anyways, all I have to do is convert it to spherical coordinates (from rectangular to spherical).
  5. Mar 8, 2009 #4


    User Avatar
    Homework Helper
    Gold Member

    I was afraid of that :wink:

    It is indeed a paraboloid, so [itex]\rho[/itex] and [itex]\phi[/itex] will not be independent the way they would if it was a spherical section....

    Try finding the relationship between [itex]\rho[/itex] and [itex]\phi[/itex] for the paraboloid's curved and flat surfaces
  6. May 10, 2009 #5
    From my weblog
    http://buyanik.wordpress.com/2009/05/02/laplacian-in-spherical-coordinates/" [Broken]
    Last edited by a moderator: May 4, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook