Statics question: when do I need to find the support reactions?

[denting]

I didn't use the format because my question is more general. I want to be able to understand the logic so I can apply it where appropriate.

We're finding forces (and whether they're in tension or compression) using the Method of Joints and Method of Sections. I don't understand why sometimes it's necessary to find the supprt reactions, but sometimes it's not. Please help. Thank you!

 

[jeffc0987]

I know in the method of joints there are certain joints that can be ignored called "zero force members" as the name implies. Since the question is so general I'm not sure if this is at all what you are looking for. there's plenty of reference material on the internet to help you out though I am sure.

 

[PhanthomJay]

It is almost always better to solve for the support reactions first before using the method of joints or sections, because it gives you more known external forces up front and makes the solution much easier. Sooner or later you'll need to find them anyway, better sooner than later.

 

[jhae2.718]

I always solve for reactions first as well.

PhanthomJay, I was looking forward to hearing your take on the question.