What is significance of torque

In summary: One advantage of defining torque as F*r^2 is that it is a more general quantity than force*acceleration. This is because it includes the rotational component of the force. Force*acceleration only includes the linear component of the force.
  • #1
Arslan
20
0
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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  • #2
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?
 
  • #3
Using a screwdriver is a rather good way to feel what torque is.
 
  • #4
let me put my question this way
why torque is defined as F*r why not F*r^2
 
  • #5
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:
 
  • #6
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.
 
  • #7
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).
 
  • #8
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?
 

Related to What is significance of torque

What is torque and how is it defined?

Torque is a measure of the twisting force that an object experiences when a force is applied to it. It is defined as the product of the force and the distance from the point of application of the force to the axis of rotation.

Why is torque important?

Torque is important because it helps us understand how forces affect the motion and stability of objects. It is crucial in many areas of science, such as mechanics, engineering, and physics, and is essential in designing and analyzing machines and structures.

What are some real-world examples of torque?

Some common examples of torque include opening a door by turning the doorknob, tightening a bolt with a wrench, and spinning a top. Torque is also important in sports, such as swinging a baseball bat or kicking a soccer ball.

How is torque different from force?

While both torque and force involve the application of a force, they are different concepts. Force is a push or pull on an object, while torque is a measure of how that force causes an object to rotate around an axis. In other words, torque is a type of force that causes rotational motion.

How is torque measured and what units is it expressed in?

Torque is typically measured in units of newton-meters (N·m) or foot-pounds (ft·lb). It can be calculated by multiplying the magnitude of the force by the distance from the axis of rotation to the point where the force is applied. In the metric system, torque is calculated using the formula τ = F x r, where τ is torque, F is force, and r is the distance from the axis of rotation.

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