How Do I Find the Missing Values for Unknown Weights in a Pulley System?

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Homework Statement


Am I heading in the right direction?
If so i am lost now in finding the missing values for the unknown weights, a little nudge would be great. The work that i have attached is CLEANED up so it can be readable.


Homework Equations





The Attempt at a Solution


 
Attachments
  • Diagram of a suspended load: a 400 N block A hangs from a spring attached to point B and from cords running over pulleys C and D, with a 3W block on the left and a W block on the right. Dimensions 840 mm, 690 mm, 360 mm and 690 mm are labelled, with the problem text printed above.
    statics.jpg
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  • sts003.pdf
    sts003.pdf
    30.8 KB · Views: 271
I finally was able to complete this problem.
First i was going in the wrong direction using unit vectors. I found out that it was a simple force vector problem. Bottom line i was over thing and making it out to be more complicated then it really was, but it was comforting to find out that i was not the only one :-) But anyway I am going to attached my solution. The professor did not use angles in his solution as i did he just used the properties of find the angle sine=opp/hyp and cos=adj/hyp. I used tan to find the angles as you can see. The one that that confuses me is how precise is precise?
Thank youI am new on here and i see that this would be a good place for practice.
 
Attachments
  • Handwritten solution to a statics problem: a force diagram of a spring-and-pulley system with blocks 3W and W, followed by equilibrium equations and the final result W = 63.14 N, l0 = 0.76 m.
    Solution002.jpg
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