Equilibrium from the ceiling. Solve using cosines

[tigerwoods99]

thanks

 

[Redbelly98]

Where is the center of the rod located, relative to point B?

 

[tigerwoods99]

I'm sorry!

 

[Redbelly98]

Yes, I realize that the rod is opposite to angle B. The question was meant to give you a clue about the configuration. So more specifically, what do we know about where the center-of-mass of the hanging rod is located, relative to the point B from which the rod and strings are hung?

 

[tigerwoods99]

I think the mg of the rod is located directly underneath point B where it is hung from the ceiling

 

[Redbelly98]

Yes, exactly. You can use that information to figure out the angle the rod makes with the horizontal.

 

[tigerwoods99]

Ok. so knowing that does angle B "split" into two halves. I am still not sure where this is taking me.!

 

[Redbelly98]

Draw a vertical line from B to the rod center. The triangle is split into two smaller ones. Solve either of the smaller triangles.

Good luck!

 

[tigerwoods99]

Ok thanks! I think i still need a little more guidance on this though. What will this solve? How will this help find theta?

 

[Redbelly98]

The key is to find the triangle's angle located at the center of the rod. If you haven't already, draw a figure including the vertical line between B and the rod center.

 

[tigerwoods99]

Ok. thanks