What is significance of torque

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    Significance Torque
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Discussion Overview

The discussion revolves around the significance and physical interpretation of torque, exploring its mathematical definition and practical applications. Participants examine the relationship between torque and rotational motion, as well as the reasoning behind its formulation as torque = force × radius.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants inquire about the practical significance of torque beyond its mathematical definition.
  • One participant suggests that torque can be understood through everyday applications, such as using a wrench or a screwdriver.
  • Another participant questions why torque is defined as F × r instead of F × r², seeking a deeper understanding of its formulation.
  • A participant explains that torque relates to angular acceleration and moment of inertia, drawing parallels to linear motion equations.
  • Some participants argue that defining torque as F × r² would not yield correct results in mechanical calculations, emphasizing the importance of the current definition.
  • There is a suggestion that angular momentum is a fundamental quantity, similar to linear momentum, and that torque plays a crucial role in rotational dynamics.

Areas of Agreement / Disagreement

Participants express various viewpoints regarding the definition and significance of torque, with no consensus reached on the alternative formulation of torque as F × r². The discussion remains unresolved regarding the implications of such a definition.

Contextual Notes

Participants mention the need for further reading to understand the rigorous mathematical relationships in rotational dynamics, indicating that some assumptions and definitions may require clarification.

Arslan
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or you can say what is the physical interpertation of torque. i know the mathemetics of it but what's its significance in practical terms.
 
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What? You mean you want to know how it applies to the real world?

Like how you use a wrench to tighten a nut on a bolt? Or rev an engine to accelerate your car?
 
Using a screwdriver is a rather good way to feel what torque is.
 
let me put my question this way
why torque is defined as F*r why not F*r^2
 
Hi Arslan! :smile:

Torque is turny-force, and moment of inertia is turny-mass.

Mass is the ratio of linear force to linear acceleration …

twice the force gives twice the acceleration.​

Moment of inertia is the ratio of torque (angular force) to angular acceleration …

twice the torque gives twice the angular acceleration. :wink:
 
Arslan said:
let me put my question this way
why torque is defined as F*r why not F*r^2

Reasonable question.
The pragmatic answer is that your suggested alternative won't give you the right answer when you try to calculate what will balance what. Torque is a quantity, like Force that can be used to model and understand mechanical situations AND to predict what will happen. The proof of the pudding is in the eating.

The more rigorous answer is that angular momentum is a very basic quantity in the Universe - just as linear momentum is. The formulae for linear motion, such as
Force = mass times acceleration
momentum = mass times velocity
and others, are well known. (?)

There are equivalents in the 'rotational world' and Torque turns up in those formulae, along with Moment of Inertia and Angular Momentum etc.
You would need to read further if you want more details and some of those formulae.
 
Arslan said:
or you can say what is the physical interpertation of torque. i know the mathemetics of it but what's its significance in practical terms.

I think of torque as a force that causes rotational motion.

F = ma; here force F causes linear motion, with linear acceleration a.

Torque τ = Iα ; α is angular acceleration and moment of inertia I is related to mass.

Similarity between this 2 equations seem to be what is linear (motion in straight line) and angular (motion in circle).
 
Arslan said:
let me put my question this way
why torque is defined as F*r why not F*r^2
What would be the advantage of defining torque as F*r^2?
 

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