B Will there be a reaction at the hinge B in this question?

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1. Apr 9, 2017

I have solved this question by completely disregarding the reaction at the hinge B. And surprisingly, answer turns out to be correct. Why is that so?

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2. Apr 9, 2017

BvU

Half the weight of AB is on B (AB doesn't rotate or move) and that gives you the $13\over2$.

For the second part I'm too lazy to work it out (you did that already); if you post your work, I (or someone else) may comment (e.g: "it doesn't matter" or "it's a numerical coincidence")

3. Apr 9, 2017

How do we know that half of AB's weight is on B?

4. Apr 10, 2017

zwierz

You have 6 scalar unknowns: two components of each reaction force at the points A,B,C. You also have three equations of statics for each rod. I wish you good luck

5. Apr 10, 2017

But Reaction at B isn't playing a role. Just explain it to me that whether is that a coincidence or there's some solid logic behind?

6. Apr 11, 2017

zwierz

How can I explain if you already know what plays role here and what does not? :)

7. Apr 11, 2017

Staff: Mentor

This should be posted in a homework forum, with an attempt at a solution.