## Statics Help: Support Reactions

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I understand the problem here, what I don't see is how to find the support reactions. Since at each joint we have more than two unknowns I have to find the support reactions. I have the answer to the problem. Could someone tell me how to find the support reactions? It seems like I need to take the moments about G and or F to get the support reactions at the pin at A and the rocker at E. Is this true?
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 Blog Entries: 47 Recognitions: Gold Member Homework Help Science Advisor It seems that you have three unknown [rectangular] components, two at A and one at E. For the structure as a whole, did you write down Newton's laws (for statics) $$\vec F_{net}=\vec 0$$ and $$\vec \tau_{net}=\vec 0$$, which yields three scalar equations [for this planar problem].. and hence three linear equations in three unknowns? By choosing to evaluate moments about A, you can simplify your system.
 Right that is what I assumed! However, I'm kind of working backwards throught this text. So I'm not finding the correct moment equations.

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 At pin A we have $$A_x and A_y$$ at the rocker E we have $$E_y$$. So shouldn't the moments be: $$M_A = 20kn-1.5A_y$$ I'm confused now! I know this is so easy when i finally see it
 Blog Entries: 47 Recognitions: Gold Member Homework Help Science Advisor Shouldn't it be "sum of the moments about A" $$M_A= (-1)(a)P_1+(-1)(3a)P_2+(1)(4a)E_y$$ ?