Feedback on the concepts surrounding pulley, ropes, friction

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SUMMARY

The discussion focuses on the mechanics of pulleys, ropes, and friction, specifically analyzing the angles of contact in two scenarios: when β is less than 90 degrees and when β is greater than 90 degrees. It establishes that friction can be utilized to reduce the pulling resistance when one force (F1) is greater than another (F2). The Capstan equation is referenced to illustrate the relationship between the forces and friction in these arrangements, emphasizing that static friction is governed by the inequality |F1 - F2| < μsN, while capstan arrangements follow the logarithmic relationship |ln(F1) - ln(F2)| < μsθ.

PREREQUISITES
  • Understanding of basic physics concepts related to forces and friction
  • Familiarity with the Capstan equation and its applications
  • Knowledge of static friction and its governing equations
  • Ability to interpret diagrams related to force angles and arrangements
NEXT STEPS
  • Study the Capstan equation in detail to understand its implications in pulley systems
  • Explore the principles of static friction and its role in mechanical systems
  • Research the effects of angle variations on force distribution in pulley systems
  • Examine real-world applications of friction in mechanical engineering and design
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Mechanical engineers, physics students, and anyone involved in the design and analysis of pulley systems and frictional forces will benefit from this discussion.

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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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