How Do You Determine the Direction of Reaction Forces in Structural Problems?

[member 392791]

Homework Statement

Problem 4.36
http://xps2pdf.co.uk/4c82ad8dcb91d5507169e0a18804ea30bf81d592/4.36.pdf

Homework Equations

The Attempt at a Solution

I am not sure if I am doing this correctly..there is a lot of information that I am not using to solve the problem (i.e. all the different distances, as well as the 30°. When determining the direction of a reaction force (Say A for example) do I just pick an arbitrary direction and if it comes out negative I know it's direction is opposite of what I put it as? I chose the moment at point A because I knew the moments of force A would be zero, leaving me with only the applied force and force E, which has a roller on it so it can only have a reaction force in one direction.

 

[PhanthomJay]

Can't open the first file, but based on your work:

Homework Statement

Problem 4.36
http://xps2pdf.co.uk/4c82ad8dcb91d5507169e0a18804ea30bf81d592/4.36.pdf

Homework Equations

The Attempt at a Solution

I am not sure if I am doing this correctly..

looks good

there is a lot of information that I am not using to solve the problem (i.e. all the different distances, as well as the 30°.

you don't need them if you are just looking for reactions

When determining the direction of a reaction force (Say A for example) do I just pick an arbitrary direction and if it comes out negative I know it's direction is opposite of what I put it as?

yes

I chose the moment at point A because I knew the moments of force A would be zero, leaving me with only the applied force and force E, which has a roller on it so it can only have a reaction force in one direction.

good!