Equilibrium - Flagpole vs Rope Tension

AI Thread Summary
The discussion revolves around calculating the tension in a rope supporting a flagpole subjected to wind force. The flagpole is in equilibrium, meaning the net forces and torques must balance. The key equations involve torque and net force, leading to the realization that tension acts in both the x-axis and y-axis. The correct formula for tension is derived as Ftension = 0.8F/cos(theta), correcting the initial misunderstanding of the relationship between the forces. The conclusion emphasizes the importance of balancing torques to find the correct tension in the rope.
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Homework Statement



A flagpole of height h has a flag attached that is being blown by the wind with force F at a height of 0.8h. In order to prevent the flagpole from blowing over a rope is run from an anchor in the ground to the top of the flagpole at an angle \vartheta. What is the tension in this rope?

Homework Equations



\tau=rFsin\vartheta
F_{}net = F_{}flag-F_{}rope=0

The Attempt at a Solution



Since the objects are in equilibrium the net force of the system must be 0. Or rather the force of the wind on the flag must be equal, and in the opposite direction, of the force of the supporting rope attached at the top of the flagpole.

Since the two forces act on different positions of the flagpole torque must be accounted for with the flagpole acting as the lever arm that is attached to the ground, but not supported by it.

Since the weight of the flagpole = the normal force on the flagpole the Tension should only act in the x-axis. This lead me to believe that the tension in the rope equals the radius times the force in the x-direction, or T = 0.8Fsin(theta) which is not the case.

This leads me to start thinking that any rope with any tension that is at an angle that is not perpendicular to an opposing force MUST have tension acting in both the x-axis and y-axis direction. In this questions the tension in the y-axis would be pulling the flagpole harder into the ground, and the normal force would increase so that the overall force of the flagpole in the y-axis direction would still be 0 overall. Now it seems like I am left with two unknowns of tension in the y-axis, and the overall tension along the hypotenuse. What am I missing?
 
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I figured out the solution. Obviously the two torques must cancel each other out.
(0.8h*F)-(Ftension*1h*cos(theta))=0
Ftension*cos(theta)=0.8F
Ftension = 0.8F/cos(theta)

NOT

Ftension = 0.8Fcos(theta)
 
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