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: Electric field of a disk & u-substitution

  1. May 25, 2016 #1
    1. The problem statement, all variables and given/known data
    Calculate the electric field at point P (refer to visual): Capture.JPG

    2. Relevant equations
    I follow everything - except how the limits of integration for the u-integral ( Capture1.JPG ) are arrived at?

    3. The attempt at a solution
    u=x2 is the smallest value u can have, and u=x2+R2 is the greatest value u can have?
  2. jcsd
  3. May 25, 2016 #2


    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    The lower limit of the u integration should correspond to the lower limit of the r integration (r = 0). So, the lower limit of the u integration is the value of u when r = 0. Similarly for the upper limit.
  4. May 25, 2016 #3
    Very helpful - thank you!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted