Finding Internal Forces With Joints & Sections

[jhox08]

I have the truss shown, I'm supposed to find the internal force for each of the vertical members...I understand method of joints and method of sections, but can you use both method of joints and sections in the same problem...for example I found Ly=52.5 and Ry=32.5 using moments and summing in the Y direction, next I used method of joints at H to find Fhg=54.17 C and Fhj=43.34 T, then I used method of joints again at J to find Fjg = 0, but then I made a cut just to the left of G and J exposing Feg, Fgk and Fjk, I found Feg=54.17 C and Fkg=0 by method of sections but used method of joints at K to find Fek=25 T and Fwk=43.34 T, so my question is can I solve this problem using both methods at the same time?...thanks

 

[nvn]

Yes, I think you can use both methods in the same problem.

 

[pongo38]

They are really the same thing. The method of joints IS the method of sections applied to a single joint. The section cut does not have to be a straight line.