Find the tension in the two wires

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    Tension Wires
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Homework Help Overview

The problem involves determining the tension in two wires supporting a traffic light, with given angles and weight. The subject area is physics, specifically focusing on forces and equilibrium in static systems.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to solve the problem using equations derived from the forces acting on the system. Some participants question the correctness of the trigonometric functions used in the equations, suggesting a possible reversal of sine and cosine terms.

Discussion Status

The discussion is active, with participants providing feedback on the original poster's approach. Some guidance has been offered regarding potential errors in the setup of the equations, but no consensus has been reached on the correct method.

Contextual Notes

There is a mention of a figure that is not provided in the thread, which may be crucial for understanding the problem setup. Participants are also working within the constraints of a homework assignment, which may impose specific rules on how the problem should be approached.

kp87
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Homework Statement


Find the tension in the two wires supporting the 36 kg traffic light shown in Fig. 12-57. (Assume that 1 = 52° and 2 = 38°.)

http://img15.imgspot.com/u/07/77/15/952alt.gif

Homework Equations


-T1cos(52)+T2cos(38)=m*g
T1sin(52)+T2sin(38)=0


The Attempt at a Solution



so I found T1=-T2sin(38)/sin(52)
and plugged into the first equation and got
[sin(38)*cos(52)/sin(52)+cos(38)]*T2=353.16
and got T2 = 278N
and T1=217N

but when I put it into the webassign it is wrong...
so what am I doing wrong?
 
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It would be useful if you presented the figure somehow.

You may want to check your trig, although I can't tell for sure.
 
i think the sins and cosines are reversed. The vertical weight mg is opposed by the sines of the respective tensions.
 
denverdoc is right. Just "swap" m*g and 0.
 
k thanks a lot got it :)
 

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