Objects in equilibrium hinged platform with cable problem

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Homework Help Overview

The discussion revolves around a problem involving a hinged platform flagpole supported by a cable, where participants are tasked with finding the tension in the cable and the forces at the hinge. The problem is situated in the context of static equilibrium, specifically analyzing forces and torques.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to set up equations based on the equilibrium conditions for forces and torques but encounters a challenge with having more unknowns than equations. Some participants question whether solving for variables in terms of others could yield a solution, while others suggest that certain variables may not be necessary.

Discussion Status

The discussion is ongoing, with participants exploring different approaches to the problem. There is acknowledgment of the complexity due to the number of unknowns, and some guidance has been offered regarding the potential simplification of variables.

Contextual Notes

Participants note the constraints of having four unknowns and only three equations, which raises questions about the setup and assumptions made in the problem. The original poster also mentions a specific angle and weight, which are critical to the problem context.

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
 
Last edited:
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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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