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: 3-D Statics

  1. Dec 14, 2007 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations
    everything is in static equilibrium

    3. The attempt at a solution

    well I know how to follow up to solution on these types of problems quite easily, however..on this one I can't seem to get started because I don't know where the weight of the of the pipe is located on the assembly...so

    1. i tried multiplying 20N/m by 6.5 (length of the pipe) I think that should give the value of the force

    2. I tried finding the centroid of the wire...but the centroid I found isn't even located on the pipe at all which really confused me

    so basically all I need to know is where this force is, so I could get started on the problem ...thanks

    Attached Files:

  2. jcsd
  3. Dec 15, 2007 #2


    Staff: Mentor

    That is actually correct. In this case the centroid is not located on the pipe. That can happen very often. Consider a disk, the centroid is the center of the disk. Now punch a hole in the center, the centroid is no longer on any material point of the ring.

    I would break the pipe into two separate segments and find the centroid of each segment individually. Those segment-wise centroids will be on the pipe. It adds some extra end-conditions at the bend in the pipe, but you know how to handle those already.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook