Feedback on the concepts surrounding pulley, ropes, friction

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The discussion focuses on the angles in pulley and rope systems, specifically the conditions when the angle of contact is less than or greater than 90 degrees. It emphasizes the role of friction in reducing the resisting force when one force exceeds another, suggesting that friction can assist the weaker force. The capstan equation is referenced to explore the effects when the forces are unequal, highlighting the logarithmic relationship between the forces and the angle of contact. The principles of static friction are also discussed, noting that friction opposes relative motion and aids the weaker force in the system. Understanding these dynamics is crucial for optimizing pulley and rope arrangements in practical applications.
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Homework Statement
Having been working on problems that included weight, ropes, pulley and friction I wanted to make a sort of reminder. But I need to know if and what changes if F2 > F1
Relevant Equations
Fx=0
Fy=0
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Revisit the angles for the two first cases.
From first diagram, β<90°.
From second diagram, β>90°.
 
really? Because I thought it goes like this
tri.png
 
goodOrBad said:
if and what changes if F2 > F1
Friction acts to oppose relative motion of the surfaces in contact. It will aid whichever of the two forces is weaker.
In the usual linear arrangement, ##|F_1-F_2|<\mu_sN## for static friction; in these capstan arrangements, ##|\ln(F_1)-\ln(F_2)|<\mu_s\theta##.
(I'm assuming each force is measured with pulling away from the frictional contact as positive.)
 
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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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