# Determining the support reactions of a frame

1. Sep 1, 2011

### hobbyenthusia

Here is a link to the problem:
http://img62.imageshack.us/img62/374/frameow.jpg" [Broken]
I am trying to find the support reactions at A and B.
I separated the frame at the hinge(call it C) into two parts and took the moment equation about point A.
This gave me: $\Sigma$Ma = -60(25) - 62.5(12.5) + Cx(25) + Cy(25)
The forces in the y:$\Sigma$ Fy = -62.5 + Cy + Ay
The forces in the x: $\Sigma$ Fx =60 + Ax - Cx

From here I am unsure what to do as I have four unknowns and only three equations.

Last edited by a moderator: May 5, 2017
2. Sep 1, 2011

### PhanthomJay

Hello hobbyenthusia(st), welcome to these forums!

Try looking at the other part of the frame that includes the support at B. That should give you a total of 6 equations with a total of 6 unknowns.

3. Sep 1, 2011

### hobbyenthusia

I completely missed that. Thank you.
After taking the moments for each side is it as simple as solving Cx in terms of Cy or vice versa and finishing it up?

4. Sep 2, 2011

### PhanthomJay

Yes, solve for Cx and Cy and the rest will follow. Please watch plus and minus signs! If Cx is assumed or found to act to the left on the left section, it must act to the right on the right section.