I think I am getting the wrong answer here, but I don't know why. Would someone please be so kind to go through this basic stuff.(adsbygoogle = window.adsbygoogle || []).push({});

Question: The force F exerts a 200 ft-lb counterclockwise moment about A and a 100 ft-lb clockwise moment about B. What are F and theta?

Attempt:

[tex] M_A = 2 F \cos \theta + 9 F \sin \theta = 200 [/tex]

[tex] M_B = -7 F \cos \theta + F \sin \theta = -100 [/tex]

A little bit of algebra yields:

[tex] \frac{\sin \theta}{\cos \theta} = \frac{12}{-11} [/tex]

[tex] \tan \theta = \frac{12}{-11} = -47.49 (deg) [/tex]

Would someone please tell me what I am doing wrong. Thanks!

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# Homework Help: Basic Statics Mechanics - moments

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