three strings and a weight, need tensions in strings


by thedarkone80
Tags: strings, tensions, weight
thedarkone80
thedarkone80 is offline
#1
Oct22-09, 12:16 AM
P: 8
1. The problem statement, all variables and given/known data
You have three strings holding a 20kg weight, all tied to a ceiling above the weight, one centered right above the weight, the other two tied to the string at equal angles. What is the tension in each of the cables

2. Relevant equations
Fnet=0


3. The attempt at a solution
Tension 1 (x)= T1 cos theta
Tension 1 (y)= -T1sin theta -n
Tension 2 (x)= 0
Tension 2 (y)=mg+T2-n
Tension 3 (x)= -T3cos theta
Tension 3 (y)= -T3sin theta -n
I really dont know if this is right, and what in the world the angle would be, i need help. Thanks
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Redbelly98
Redbelly98 is offline
#2
Oct22-09, 08:03 PM
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Quote Quote by thedarkone80 View Post
3. The attempt at a solution
Tension 1 (x)= T1 cos theta
Tension 1 (y)= -T1sin theta -n
Tension 2 (x)= 0
Tension 2 (y)=mg+T2-n
Tension 3 (x)= -T3cos theta
Tension 3 (y)= -T3sin theta -n
I really dont know if this is right, and what in the world the angle would be, i need help. Thanks
For a problem like this, you need to:

1. Draw a free body diagram , showing each force that acts on the weight.
2. Set up separate Fnet=0 equations for the horizontal and vertical directions.

Have you drawn the free body diagram ? If it's not easy to post the drawing, can you at least list all the forces acting on the weight?


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