A doubt respect to the sign of the torsor (torque)

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Discussion Overview

The discussion revolves around a homework problem related to torque and forces in a mechanical system. Participants are examining discrepancies in the values of forces used in calculations and the sign of torque along a specific axis, as well as the implications of the action-reaction law.

Discussion Character

  • Homework-related
  • Debate/contested

Main Points Raised

  • The original poster questions why the solution to the problem states Force 2 as 10 N when they calculated it as 416.7 N.
  • There is confusion regarding the sign of the torque along axis CD, with the original poster asserting it should be negative based on the action-reaction law.
  • One participant suggests that the book's solution showing F2 = 10 N seems incorrect.
  • Another participant indicates that the direction of the net torque may have been labeled incorrectly, suggesting it should be clockwise due to the larger force F2.

Areas of Agreement / Disagreement

Participants express differing views on the correct values and signs for the forces and torque, indicating that multiple competing interpretations exist. The discussion remains unresolved regarding the correct values and directions.

Contextual Notes

There are unresolved assumptions regarding the definitions of forces and torque directions, as well as the specific context of the problem statement and diagram.

Queren Suriano
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Homework Statement



upload_2015-5-1_22-50-1.png


Actually I have two doubs, the first one is Why in the solution of this problem, in the sumatory of moments in C, Force 2=10?? If in the sumatory of moments in F, Force 2 is 416.7 N. Actually I calculate with 416.7 N, and T in C = 100 N. The other doubt is with the sign of the torsor along the axis CD. Because the action-reaction law, the torsor in the axis will enter in the axis, thus it will NEGATIVE, but the solution takes positive!. Why??
upload_2015-5-1_22-55-32.png


Homework Equations



upload_2015-5-1_22-56-11.png
upload_2015-5-1_22-56-19.png

The Attempt at a Solution


It is in the The problem statement, at the picture
 

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phinds said:
I can't answer your questions but I would point out to you that as far as I can tell, you don't have any doubts at all, what you have is questions.

https://www.physicsforums.com/showthread.php?t=607274

Ok, thank you for correcting my grammar. It's true, I have 2 questions
 
I understood what you meant by "doubt"... :smile:

You are saying that the book's solution shows F2 = 10N? That seems way off...

And as for the direction of the net torque on the center gear, I think you have labeled the direction incorrectly. The force F2 on the bottom of the gear is larger, so the net torque will be towards the back of the apparatus (clockwise as seen from the front)...
 
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berkeman said:
I understood what you meant by "doubt"... :smile:

You are saying that the book's solution shows F2 = 10N? That seems way off...

And as for the direction of the net torque on the center gear, I think you have labeled the direction incorrectly. The force F2 on the bottom of the gear is larger, so the net torque will be towards the back of the apparatus (clockwise as seen from the front)...
Thank you
 

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