What Are the Tensions and Forces in a Multi-Pulley System?

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SUMMARY

The discussion focuses on analyzing tensions in a multi-pulley system, specifically identifying the tensions T1 through T5. It is established that T1 equals mg, where m is the mass and g is the acceleration due to gravity. T2 and T3 are determined to be equal, each sharing the weight, thus T2 = T3 = 1/2mg. T4 is concluded to equal mg + F to maintain system equilibrium, while T5 is also identified as mg, confirming that the system remains stationary without acceleration.

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  • Understanding of Newton's laws of motion, particularly F=ma.
  • Knowledge of tension in ropes and its implications in pulley systems.
  • Familiarity with concepts of massless pulleys and frictionless systems.
  • Basic grasp of gravitational force and its role in static equilibrium.
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  • Investigate the effects of friction and mass in pulley systems for comparative analysis.
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narfarnst
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Homework Statement


http://i829.photobucket.com/albums/zz220/narfarnst/problem.jpg

Find T1 through T5 and the force on the right side of the diagram above.
(The force balances the weight, so the system is stationary).
EDIT: Oh, and the pulleys and ropes are massless and there is no friction.

Homework Equations


F=ma, various rearrangements of T=m(g+/-a)

The Attempt at a Solution


Based on mostly intuition I've concluded that T1=mg (very sure about that one).
I also think that T2 and T3 equally share the weight, so T2=T3=1/2mg.
T4 has to equal mg+F for it to keep the system up
And I'm not sure about T5 but I'm thinking that it equals mg because the system isn't accelerating.
But I'm not at all 100% sure an these.

Thanks!
 
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The single rope has three segments. Each segments must have the same tension. That is the basic constrain in the pulleys.
 
narfarnst said:
Based on mostly intuition I've concluded that T1=mg (very sure about that one).
Intuition is fine, if you can then find a reason why it is so. Gravity and
the tension of the rope are the only forces on the block, so they
must be equal and opposite.

I also think that T2 and T3 equally share the weight, so T2=T3=1/2mg.
Because the pulleys have no friction and no mass, there must be the
same tension in the ropes on both sides. (if there were not they would
start to accelerate infinitely fast)
T4 has to equal mg+F for it to keep the system up
Ok
And I'm not sure about T5 but I'm thinking that it equals mg because the system isn't accelerating.
but then the forces on the top pulley would be unbalanced
 

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