# Engineering Statics Equilibrium System Question

1. Jun 3, 2014

### Temp0

1. The problem statement, all variables and given/known data
http://i.imgur.com/VFb5rwj.png

2. Relevant equations

3. The attempt at a solution
First, I drew the FBD for the system, one horizontal force at A, one force perpendicular to the beam at B, and the weight.
Writing out the equilibrium equations:
The sum of forces in the y direction should be 0, so I have the equation:
Nb cos(θ) - W = 0, which can be rearranged for Nb later on.
Then I took the moment about point A:
Nb (a/cosθ) - Wcosθ (L/2) = 0
Eventually, it simplifies out to cos^-1 ( (2a/L) ^(1/3) ) = θ

I don't think I got the right answer, but can someone help me identify my error? Thank you in advance.

2. Jun 4, 2014

### paisiello2

Why do you think you have the wrong answer?

3. Jun 4, 2014

### Temp0

IDK, it looks just so completely wrong. and also it says that describe it in terms of w, a, and l and I have no w.

4. Jun 4, 2014

### paisiello2

Would changing W also change θ?

Also your answer is consistent with the units. If W was in the solution then the units would get screwed up.

5. Jun 5, 2014

### Temp0

Hmm, I suppose you're right, thank you for the replies.