Optimizing Cable Direction for Minimum Force in Vector Addition of Forces

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The discussion focuses on determining the direction of a third cable to minimize its force while maintaining a resultant force from two known cables. The user has calculated the resultant force (FR) from the two cables, yielding a magnitude of approximately 1605.28. However, there is confusion regarding the term "minimum" in the context of the problem. The goal is to find the angle θ that minimizes the force F in the third cable while balancing the resultant force. Clarification on the method to achieve this minimum force is requested.
Suy
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Homework Statement


Three cables pull on the pipe such that they create a resultant force having magnitude FR. If two
of the cables are subjected to known forces, as shown in the figure, determine the direction θ of
the third cable so that the magnitude of force F in this cable is a minimum. All forces lie in the
x–y plane.What is the magnitude of F? Hint: First find the resultant of the two known forces.
Prob._2-31.jpg

Homework Equations





The Attempt at a Solution


I have the solution
but i don't understand "minimum" in this question?
"the third cable so that the magnitude of force F in this cable is a minimum. "
 
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Suy said:
...determine the direction θ of the third cable so that the magnitude of force F in this cable is a minimum.

F_{R}=\left[1200sin45\textdegree+800cos30\textdegree\right]\hat{i}+\left[1200cos45\textdegree-800sin30\textdegree\right]\hat{j}

F_{R}=1541.35\hat{i}+448.53\hat{j}

\left|F_{R}\right|=1605.28

tan^{-1}\left (\frac{448.53}{1541.35}\right)=16.22\textdegree

Cheers!
 
wat is the solution...can u give me?
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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