Can Torque Be Applied to an Object Through Linear Forces Alone?

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Homework Help Overview

The discussion revolves around the concept of torque and its application through linear forces. Participants are exploring the relationship between moments and forces, particularly in the context of a problem involving a specified moment and its implications.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning why a moment is not calculated as a product of force and distance in certain contexts. There is a discussion about the nature of applied moments versus linear forces, with some participants seeking clarification on how moments can be applied practically.

Discussion Status

The discussion is ongoing, with participants actively questioning the definitions and applications of torque and moments. Some guidance has been offered regarding the distinction between applied moments and linear forces, but no consensus has been reached on the practical implications of these concepts.

Contextual Notes

There is an implied constraint regarding the context of the problem, as participants note that the application of torque as described may not reflect everyday scenarios.

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Homework Statement


Why the moment isn't=15* 3Nm? Since we are taking moment about point O...it's 3m away from O

Homework Equations

The Attempt at a Solution

 

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goldfish9776 said:

Homework Statement


Why the moment isn't=15* 3Nm? Since we are taking moment about point O...it's 3m away from O

Homework Equations

The Attempt at a Solution

Are you referring to the 15kNm moment that is applied? You don't multiply that by a distance. (It would give you something with units kNm2.) a force times a perpendicular distance gives a moment, but an applied moment is already a moment. Exactly where it is applied makes no difference, only its magnitude and direction matter.
 
haruspex said:
Are you referring to the 15kNm moment that is applied? You don't multiply that by a distance. (It would give you something with units kNm2.) a force times a perpendicular distance gives a moment, but an applied moment is already a moment. Exactly where it is applied makes no difference, only its magnitude and direction matter.
ya , i knew that . But , how can be moment be applied? only force can be applied , right?
 
goldfish9776 said:
ya , i knew that . But , how can be moment be applied? only force can be applied , right?
Are you asking as a practical matter how it is possible to apply a moment as opposed to a force? There does not need to be a way to do that. Consider turning a nut using a spanner. One can think of it as applying a torque, or as applying two equal and opposite forces along parallel but different lines of action. If you are told a moment of some specified magnitude and direction is applied, you do not need to care about how it is applied.
 
haruspex said:
Are you asking as a practical matter how it is possible to apply a moment as opposed to a force? There does not need to be a way to do that. Consider turning a nut using a spanner. One can think of it as applying a torque, or as applying two equal and opposite forces along parallel but different lines of action. If you are told a moment of some specified magnitude and direction is applied, you do not need to care about how it is applied.
yes, this will only occur in the exercise , but not in daily life ?
 
goldfish9776 said:
yes, this will only occur in the exercise , but not in daily life ?
I cannot think of a way to apply a torque to an object (in an inertial frame) other than by a combination of linear forces.
 

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