Another static equilibrium question

[SteelDirigibl]

Homework Statement

Homework Equations

M=fd
M= r x F

The Attempt at a Solution

this question really loses me. I'm not sure what exactly it is asking for, much less how to solve it. I am assuming it want's the force on A and E? I suppose I need to find the moment about each point, to help solve, but I can't seem to figure it out. moments have been tripping me up more than they should, and I'm not sure where to go. I doubt I'll get this solved in time to have turned in, but better learned late than never. Where do I go from here?

 

[Femme_physics]

Even if you have no direction as how to solve, you should draw the free body diagram and just write out the statics equations (sum of all forces/moments...) and try them out.

I'm still a student myself but I don't think this question is much of a problem. Anyway, I'll see how I can be more effective. You're right, The question is asking for the reactions at the supports A and E. Let's start with calculating sum of all moments on A. You got P, you got the 4000 [N] force that you need to break it down to its Y and X component. And there's also a reaction in E whose vetor pushing to the opposite direction of the wall. This is your unknown, and you have the distance (3.6)... can you find E from that?

 

[SteelDirigibl]

so, moment about A would be 500*9.2-cos(27)*4000*4.6=-11795 Nm

then we divide that by the distance? (3.6)

and force at F is 3276. Should it be towards the wall (negative) or away (positive)

 

[Femme_physics]

Good job! And good question. The support force is pushing against the 4000 [N]...really all the forces in the equaion, including P, are "fighting against" that major force from causing any movement. Think about the "fighting direction" of E. If it wasn't that, that force would jam that structure inside the wall where E is, with A providing its rotation axis.