Solving Torque: R=9cm, F=18N, d=30cm

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Homework Help Overview

The discussion revolves around calculating the torque exerted on a disk being pulled by a force applied via a string. The parameters include a disk radius of 9 cm, a force of 18 N, and a string unwound distance of 30 cm.

Discussion Character

  • Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the formula for torque and its application, with one participant attempting to calculate torque using the formula τ = R * F. There is a question about whether the force is applied tangentially or at an angle, which affects the torque calculation.

Discussion Status

Some participants affirm the calculation approach, while others seek clarification on the setup and parameters of the problem. There is no explicit consensus on the correctness of the torque value calculated.

Contextual Notes

Participants mention that the problem is a standalone question, indicating that it does not relate to a larger context or series of problems.

ohheytai
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what is the torque??

A disk of radius R = 9 cm is pulled along a frictionless surface with a force of F = 18 N by a string wrapped around the edge.


At the instant when d = 30 cm of string has unwound off the disk, what is the torque exerted about the center of the disk?



i tried \tau = R*F but it did not work can someone help me?
 
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ohheytai said:
i tried \tau = R*F but it did not work can someone help me?
Seems right to me. Show exactly what you did.
 


i did .09m*18N and got 1.62 N*m but its wrong
 


ohheytai said:
i did .09m*18N and got 1.62 N*m but its wrong
Is the string tangent to the disk or at an angle?
 


tangent
 


ohheytai said:
tangent
Then I'd say that you answer is correct.

Post the entire problem including any diagrams.
 


okay here it is
 

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I'd say your answer is correct. The distance is irrelevant.

Is this a stand alone problem or just one part of a longer problem?
 


stand alone.
 
  • #10


ohheytai said:
i did .09m*18N and got 1.62 N*m but its wrong

the answer is <0,0,-1.62> N*m lol :)
 

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