Finding the force on a cord from a pulley

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Discussion Overview

The discussion revolves around determining the force on a cord from a pulley system, specifically focusing on the force in the lower segment of String R, which supports a mass m. Participants explore the scenario's dynamics, including the relationships between forces and tensions in the strings involved.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant seeks assistance in calculating the force on String R, indicating they have all other variables defined.
  • Another participant questions whether a mass m is indeed hanging from String R, seeking clarification on the scenario.
  • There is a suggestion to move the discussion to a Homework Help section, implying a structured approach may yield better responses.
  • A participant notes the apparent simplicity of the problem, suggesting that if the system is static, the force calculation should be straightforward.
  • One participant recommends drawing a free body diagram to visualize the forces acting on the pulley, emphasizing the importance of understanding the system's equilibrium.
  • Another participant raises a question about the relationship between the tension in the upper and lower parts of String R, highlighting its significance for the learner's understanding.

Areas of Agreement / Disagreement

Participants generally agree on the need for clarity regarding the mass involved and the importance of visual aids like free body diagrams. However, there is no consensus on the specific calculations or methods to determine the force on String R.

Contextual Notes

Some participants express uncertainty about the calculations and the overall problem statement, indicating that additional details may be necessary for a complete understanding.

Johno123
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(Mentor note: moved from General Eng hence not homework template)

upload_2018-8-31_16-3-6.png


This is the given scenario. I'm trying to find the 'String R (lower part)' force. I know every other variable (the angles, string L and string R and the Rectangle is a mass m). Any help would be appreciated!
 

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Is that a mass m hanging from String R?
 
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256bits said:
Is that a mass m hanging from String R?

Yes sorry I forgot to put that in! Just fixed it.
 
Johno123 said:
Yes sorry I forgot to put that in! Just fixed it.
Hi again.
If this is homework, we have a section called Homework Help, to which it can be moved.
Is it homework?

It has an outline to follow, which gives you a much better responses from people who will guide you to a solution.
 
256bits said:
Hi again.
If this is homework, we have a section called Homework Help, to which it can be moved.
Is it homework?

It has an outline to follow, which gives you a much better responses from people who will guide you to a solution.

No its not homework. I'm doing some study ahead for my course next year and I wanted some help with this question.
 
Johno123 said:
No its not homework. I'm doing some study ahead for my course next year and I wanted some help with this question.
So what have you tried so far?
It is difficult to tell where you are having trouble without showing some of your calculations and equations.
 
Johno123 said:
I'm trying to find the 'String R (lower part)' force.
That's confusing to me.
It looks like a trivial question because string R's lower segment just holds up mass M.
Yet you titled your thread :
"force on a cord from a pulley"

If nothing is in motion that seems straightforward to find.

Have you drawn a free body diagram of that pulley showing the forces on it? Since nothing is moving you can make believe everything is glued together.
 
256bits said:
Is that a mass m hanging from String R?
That was probably a hint rather than a question.
 
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It like be interesting to see the whole problem statement.
 
  • #10
Do you know how the tension in string R in the upper part compares with the lower part? If you are studying ahead, this is an important part of your learning.
 
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