What is "Torque" ..??...(FOOLS!!!?)

What is "Torque"?

  • "Torque" is a measure of "force" around an axis

    Votes: 8 66.7%

  • "Torque" is a measure of "Energy" (applied/available)..or whatever

    Votes: 4 33.3%
  • Total voters
    12
  • Poll closed .
SammoHung

SammoHung

Totally agree with the thread lock....LOL...

although it was a blatent diversion from the topic: http://www.micra.org.uk/showthread.php?t=27257
... I got carried away in the thrill of physics supemecy!!...PMSL

Ed, I love our ocasional banter...lol

Dear all: Torque is a measure of "Energy" (not a measure of rotational force (A frustrating laymans equivelent description"..(lol))..."rotational force"....lol....

the subject of circular motion & SHM can be confusing when relating the principles to popular measurements in every day life...

who's with me ( or against me...lol)
 
I'll recite the post I made in the other thread.

think of a set of scales balanced with 1kg on each side. It does not make sense to think of the torques or moments in terms of energy, as at equilibrium no energy is transfered, but the torque exists.

I don't see how you can argue with that :)
 
richj said:
I'll recite the post I made in the other thread.

think of a set of scales balanced with 1kg on each side. It does not make sense to think of the torques or moments in terms of energy, as at equilibrium no energy is transfered, but the torque exists.

I don't see how you can argue with that :)
Click to expand...


yes, not just equal between the two sides...(your argument)....but an equalibrium between the three....the left mass...the right mass....and the coil-spring constant :)

VOTE and be silent...lol


(one big friendly debate)...
 
lol

nonsence

I vote for torque NOT being a measure of energy, because it isn't. lol

Not even nearly.
 
surely, a torque wrench (for example) only rotates while the torque value is rising, and settles on a value when you stop rotating it, so the final lb/ft reading is static, whereas hp is a dynamic force
 
Your poll is miss leading, and I would go so far as to say irrelevant!!!!!

1 joule is approximately equal to:

I think this could even apply: e=MC^2 In which case everything has energy "(applied/available)..or whatever".

Even that 2p piece sitting on my desk. Trouble is that doesn't make it in anyway valid to the discussion. Hence in my opinion it being irrelevant. More to the point its accepted that Joules is not to be used as a measurement of torque, for the reasons I already mentioned and will copy again here:

The joule, which is the SI unit for energy or work, is also defined as 1 N m, but this unit is not used for torque. Since energy can be thought of as the result of "force dot distance", energy is always a scalar whereas torque is "force cross distance" and so is a (pseudo) vector-valued quantity. The dimensional equivalence of these units, of course, is not simply a coincidence: a torque of 1 N m applied through a full revolution will require an energy of exactly 2π joules.

Mathematically,

c873509a4725f5cc973a341db1c889f9.png
where

E is the energyτ is torqueθ is the angle moved, in radians.
Click to expand...

Therefore I conclude that although what you state is correct, and your just trying to be a smart arse :p lol, its not in the correct context to what it is we are trying to apply this information to!
 
As I understand torque is a force appallied to the rotating bodies such as axials, flywheels, tyres about their axis, the force is either applied or emitted by a rotational body e.g when wheels turn the engine applies the force through the centre shaft and the wheel starts turning so the force is being applied by the engine and then emitted by the wheel which starts to turn and do thenusefull work i.e moves the car, or the force can be applied such as when turning the bar of a spanner, so you apply the force to the bar and the bar then turns its axis and transmits the force into the middle of the axis. such as when tightening nut and bolts.

But I coulod easily be wrong!!! there are far better knowledgable scientist out there!!
 
there is no smart arse about it. Torque is the cross product between the distance vector and force vector. This has nothing to do with energy, as shown by eds equation, E = T theta, not E = T. Two kids sitting on a seesaw, they weigh the same, the seesaw is in the middle. The two kids are at rest, there is no change in energy until one goes up and one goes down. The kids both have gravitational potential, but until one of them gives gp to the other, energy is not involved - its nonsense.
 
True, torque cannot be energy, it is a force (energy) applied to a rotating object in order to yield some work. i.e rotational motion.
 
sort of, at the end of the day the Meter referred to by a NM of torque is a different meter than is referred to by a NM of energy. The only reason I have gone out of my way to make this point, is torque is a quantity that tends to be massively misunderstood. It doesn't help to confuse people discussing something that is essentially semantics.
 
Where I get a lot of confusion is the relationship between torque and Bhp, if torque is a force so is the hp, so why the two are different and yet they coinside at around 5200RPM is beyond my brains!!!
 
Ed said:
Therefore I conclude that although what you state is correct, and your just trying to be a smart arse :p lol, its not in the correct context to what it is we are trying to apply this information to!
Click to expand...

you've got me cornered on the context point...touché!

:)...lol

richj said:
Two kids sitting on a seesaw, they weigh the same, the seesaw is in the middle. The two kids are at rest, there is no change in energy until one goes up and one goes down. The kids both have gravitational potential, but until one of them gives gp to the other, energy is not involved - its nonsense.
Click to expand...

energy is involved, and its the conservation of energy and newton's 3rd law that keeps them still:

for equilibriam the force acting at the ends of the see-saw creates stress in the see-saw arm....the arm bends a little resulting in strain....Potential energy is then stored in the arm of the see saw...the longer teh arms the greater the stored energy for a given force
 
yes but notice I addressed that in my post: - "at rest", i.e after the seesaw has bent slightly. There are two torques, but no energy is transfered. So to say there is 100Joules of Torque would be silly, wouldn't it?
 
i don't know which one to vote,

i always saw Energy and Force as the same thing. Force is the name of the energy transfer,

so if you push something you are applying a force and using energy, as the force goes up so does the required energy needed to create it.

so in my mind it is the same thing, it just depends on which way you want to use it, if you want to mesure how much energy your car uses, or how strong the force is that its applying.

really i think i answered my own question lol, it is a force, but can be mesured as energy as well.
 
here we go...

Horsepower is defined as work done over time. The exact definition of one horsepower is 33,000 lb.ft./minute. Put another way, if you were to lift 33,000 pounds one foot over a period of one minute, you would have been working at the rate of one horsepower. In this case, you'd have expended one horsepower-minute of energy.

if you have a single cylinder engine with a huuuge piston 10ft accross moving very slowly it will generate a lot of torque as the leverage on the crank will be so huuge. if you have a smaller 12cylinder engine with tiny pistons it will produce alot of horsepower due to the acceleration of the total mass. but will produce very little torque.



basicaly if you have a spanner on a nut Torque is the length of the spanner and power is the size of your arm. you can put as much power and weight and mass into the spanner as you like but you will only be able to exert a finite amount of torque on the object. but you may exceed countless numbers of horse power (or even ps)

and the reason your bhp and torque graph cross is because the leverage of the con rods on the crank (torque) is being overtaken by the number of leverages on the crank (rotations) per minute (HP).


on a dyno it is measuring how much torque (turning force) is applied by braking the wheels using the rollers. horsepower is how quickly it accelerates at a given torque.
 
richj said:
...There are two torques, but no energy is transfered.
Click to expand...
but energy does not have to be, being transfered to be present..it can still be there even iof it is static / not transforming from one form of energy to another

Just like the energy stored in a battery...its there even if theres no circuit

richj said:
So to say there is 100Joules of Torque would be silly, wouldn't it?
Click to expand...
....it sounds beutifull to me...100Joules of torque either side of the see saw each acting equal and opposite therefore net torque of teh system = 0


nahhh, youre right I prefer newton meters too

------------
 
your all talking about potential energy. a rock has no potential energy until lifted. the further its lifted the greater its potential energy.

this is different to torque. but agreed, a static object can have torque. or why else would you torque down a bolt? its being held by torque.
 
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