Objects in equilibrium hinged platform with cable problem

AI Thread Summary
A hinged platform flagpole weighing 500 Newtons is supported by a cable, and the problem involves calculating the tension in the cable and the forces at the hinge. The equations for horizontal and vertical forces, as well as the sum of torques, were established, but the user faced a challenge with four unknowns and only three equations. The correct tension in the cable is found to be 500 N, with horizontal and vertical hinge forces of 433 N and 250 N, respectively. The discussion highlighted the importance of simplifying the equations to solve for the unknowns effectively. Ultimately, the user realized that one variable could be eliminated, leading to a clearer solution path.
BrainMan
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Homework Statement


A hinged platform flagpole weighing 500 Newtons is supported in the horizontal position by a cable as shown in figure 4.35
db4208af-4577-4e0c-9851-aba4c6f18afb.jpe
. Find the tension in the cable and the horizontal and vertical forces at the hinge. Angle ø = 30°

Homework Equations


∑F=0
∑T=0
T= F* the lever arm

The Attempt at a Solution


What I did was created the three equations R cos θ -T cos 30=0 for the X forces
where R is the resultant force of the wall acting on the hinge of the beam and T is the tension in the wire. The equation for the Y forces was R sin θ + T sin θ -500=0. Then I made the equation T sin 30 (x) -500 (1/2)(x)=0 for the sum of the torques is zero. My problem is I have four unknowns and only three equations meaning I can't substitute. What do I do now? The correct answer is T = 500 N and Rx= 433 N Ry= 250 N
 
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Maybe just go ahead and solve for R and T in terms of x and theta and see what happens.
 
I don't think that will work because you have more unknowns than you have equations to work with. I tried it and it doesn't seem to work.
 
if you did it correctly then I think you would see that one of those variables actually drops out
 
Ok I see it now thanks!
 
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