1. The problem statement, all variables and given/known data http://imageshack.us/photo/my-images/851/45009287.png/ The problem(s) are shown in the link, but I'm having trouble getting them started. 2. Relevant equations 3. The attempt at a solution For 3-12: I think what I need to do is find the tension force in the ropes leading from each block to point A. Then with those forces I find the Sum of the forces in X and Y From there i think i know what to do, its just that i dont know how to find the force in each rope! My attempt: For block B, the force in the the rope to point A is sin∅/200lb. For block C, the force in the rope to point a is sin(30)/100 =50lb . Is this correct so far?
No. First things first. What's the tension in the rope connecting to B and the rope connecting to C? Hint: No calculation is required. (Consider the forces on B and C.) Then you can worry about the force components acting on point A. Careful how you write things: don't confuse sin(30)/100 with 100*sin(30).
I got it figured out, I was definately over thinking it. The tension in the ropes are equal to the weight of the blocks, so rope AB is 200lb and AC is 100lb. Then I find the Sum of forces for X and Y and solve for the unknowns! Thanks!