Engineering Mechanics- Forces

1. Sep 13, 2014

CivilSigma

1. The problem statement, all variables and given/known data
For the structure and loading of Prob. P2.46 a) determine the value of $$\alpha$$ for which the tension in cable BC is as small as possible b) the corresponding value of the tension

2. Relevant equations
Finding the components of forces, or constructing a triangle of forces - I know how to do b) but not a)

3. The attempt at a solution
I remember my professor mentioning that in order for a force to be as small as possible, we need to have the triangle of forces in a right angle triangle. I do not know how to setup the problem, if someone can help me with that I would appreciate it.

Thanks!

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2. Sep 13, 2014

SteamKing

Staff Emeritus
Why don't you start by setting up a free body diagram of the boom AC?