Horsepower vs Torque thread
02-04-2002, 02:35 AM
#81
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Re: Horsepower vs Torque thread I have seen it posted a few times in this thread that you can have 1,000,000 pds of torque but the car is not going to move. Well this is a very false statement."
I NEVER once said that if you apply 1,000,000 lbs of TQ to a car that it wouldn't move (how absurd!) I said, "You can have 1,000,000,000,000,000,000,000,000,000 ft lbs of TQ, but if you don't have ANY HP to go with it, YOUR CAR WILL SIT STILL!"
That is hypothetical but correct statement. The point is, if your car does move (which obviously it would), HP has taken place.
Please, read my comments carefully. <img src="gr_stretch.gif" border="0">
[ February 04, 2002: Message edited by: Colonel ]</p>
I NEVER once said that if you apply 1,000,000 lbs of TQ to a car that it wouldn't move (how absurd!) I said, "You can have 1,000,000,000,000,000,000,000,000,000 ft lbs of TQ, but if you don't have ANY HP to go with it, YOUR CAR WILL SIT STILL!"
That is hypothetical but correct statement. The point is, if your car does move (which obviously it would), HP has taken place.
Please, read my comments carefully. <img src="gr_stretch.gif" border="0">
[ February 04, 2002: Message edited by: Colonel ]</p>
02-04-2002, 04:06 PM
#82
Re: Horsepower vs Torque thread [quote]Originally posted by Colonel:
I NEVER once said that if you apply 1,000,000 lbs of TQ to a car that it wouldn't move (how absurd!) I said, "You can have 1,000,000,000,000,000,000,000,000,000 ft lbs of TQ, but if you don't have ANY HP to go with it, YOUR CAR WILL SIT STILL!"
<hr></blockquote>
<img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0">
I NEVER once said that if you apply 1,000,000 lbs of TQ to a car that it wouldn't move (how absurd!) I said, "You can have 1,000,000,000,000,000,000,000,000,000 ft lbs of TQ, but if you don't have ANY HP to go with it, YOUR CAR WILL SIT STILL!"
<hr></blockquote>
<img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0">
02-05-2002, 10:20 AM
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Re: Horsepower vs Torque thread I can't believe you guys are still stuck on semantics! <img src="gr_grin.gif" border="0">
Saying a car won't move if you applied 1 bajillion pound-feet of torque unless there is horspower is backwards. The correct way to describe what is happening in that situation is to say there is no horsepower because the car is not moving. <img src="gr_stretch.gif" border="0">
You simply cannot make horspower without torque and RPMs.
You need both torque and RPMs. Torque is the force. RPM's are the rotational distance. Put them both together and you have work. Do a certain amount of work in a certain amount of time and you have a rate of work being done.
That rate is called Horsepower.
To say torque is more important than HP, or vice-versa, only shows the lack of understanding of the relationship between the two.
It's simple really. Increase torque while keeping RPM's constant, and you will increase HP. Increase RPM's while keeping torque constant and you will increase HP. Increase both torque and RPM's, and you will increase HP even faster.
What's so hard to understand about this? <img src="gr_images/icons/wink.gif" border="0">
Saying a car won't move if you applied 1 bajillion pound-feet of torque unless there is horspower is backwards. The correct way to describe what is happening in that situation is to say there is no horsepower because the car is not moving. <img src="gr_stretch.gif" border="0">
You simply cannot make horspower without torque and RPMs.
You need both torque and RPMs. Torque is the force. RPM's are the rotational distance. Put them both together and you have work. Do a certain amount of work in a certain amount of time and you have a rate of work being done.
That rate is called Horsepower.
To say torque is more important than HP, or vice-versa, only shows the lack of understanding of the relationship between the two.
It's simple really. Increase torque while keeping RPM's constant, and you will increase HP. Increase RPM's while keeping torque constant and you will increase HP. Increase both torque and RPM's, and you will increase HP even faster.
What's so hard to understand about this? <img src="gr_images/icons/wink.gif" border="0">
02-05-2002, 10:35 AM
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Re: Horsepower vs Torque thread [quote]Originally posted by ChrisB:
<strong>Okay, let's go back to my original example - 300ft-lbs of torque average. Let's say that was at an average of 10500rpm. So that was an average of 600hp.
Now let's say it was at an average of 5250 rpm. That's an average of 300hp.
So you are saying that it doesn't matter if one has 600hp, the other 300hp, since the both put down an average of 300ft-lbs of torque they will both run about a 13.2@105.
Plug the values (600 and 300) in my formula above - you will get radically different ET's - as you would in real life. Yet you are claiming they would both be the same.
Again, please provide me with your mathematical proof.
Chris</strong><hr></blockquote>
Chris, c'mon. <img src="gr_stretch.gif" border="0"> what you described using your formula is not a "mathematical proof" either.
Your formula is what engineers call a linearization of what's going on to simplify a mathematical model. It's done all the time, so there's nothing wrong with it, but it is not a mathematical proof.
If you are allowed to make assumptions (the averages you mentioned), then I can make the same type of assumptions with vehicle weight, average RPMs, and using just torque figures and arrive at similar conclusions about the ET and MPH. It's not "impossible". Far from it.
Your formula is a linearization tailored to fit the data. It is a relatively simple matter to tailor another formula using only torque. It will require "assumptions" of one more parameter, but your formula is also making assumptions, so there is no foul. <img src="gr_images/icons/wink.gif" border="0">
[ February 05, 2002: Message edited by: Dean98TA ]</p>
<strong>Okay, let's go back to my original example - 300ft-lbs of torque average. Let's say that was at an average of 10500rpm. So that was an average of 600hp.
Now let's say it was at an average of 5250 rpm. That's an average of 300hp.
So you are saying that it doesn't matter if one has 600hp, the other 300hp, since the both put down an average of 300ft-lbs of torque they will both run about a 13.2@105.
Plug the values (600 and 300) in my formula above - you will get radically different ET's - as you would in real life. Yet you are claiming they would both be the same.
Again, please provide me with your mathematical proof.
Chris</strong><hr></blockquote>
Chris, c'mon. <img src="gr_stretch.gif" border="0"> what you described using your formula is not a "mathematical proof" either.
Your formula is what engineers call a linearization of what's going on to simplify a mathematical model. It's done all the time, so there's nothing wrong with it, but it is not a mathematical proof.
If you are allowed to make assumptions (the averages you mentioned), then I can make the same type of assumptions with vehicle weight, average RPMs, and using just torque figures and arrive at similar conclusions about the ET and MPH. It's not "impossible". Far from it.
Your formula is a linearization tailored to fit the data. It is a relatively simple matter to tailor another formula using only torque. It will require "assumptions" of one more parameter, but your formula is also making assumptions, so there is no foul. <img src="gr_images/icons/wink.gif" border="0">
[ February 05, 2002: Message edited by: Dean98TA ]</p>
02-05-2002, 11:10 AM
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Re: Horsepower vs Torque thread [quote]Originally posted by Colonel:
<strong>You can apply that TQ to a wrench for 15 million years if you want and if nothing moves, you've still done [b]NO WORK[/b</strong><hr></blockquote>
Applied torque to a torque wrench is known as deflection, deflection is movement, so movement is work. You do not know how a torque wrench works! A bolt does not have to turn, to produce work. Just applying force to the end of a torque wrench and producing that deflection, which is measured and translated into ft lbs. Yes one degree of deflection is movement, even 1 minute of 1 degree is movement, which is all work. Maybe you should go look up up how a torque wrench works. I still want to watch you apply 300 ft lbs of force to a torque wrench for 15 million years and tell me you are doing no work. You are exerting energy from your body to produce the force to register 300 ft lbs of torque, which is deflection, which is movement, which is work.
Now who gets to drive your car while you are doing this? <img src="gr_images/icons/cool.gif" border="0">
[ February 05, 2002: Message edited by: BigBake ]</p>
<strong>You can apply that TQ to a wrench for 15 million years if you want and if nothing moves, you've still done [b]NO WORK[/b</strong><hr></blockquote>
Applied torque to a torque wrench is known as deflection, deflection is movement, so movement is work. You do not know how a torque wrench works! A bolt does not have to turn, to produce work. Just applying force to the end of a torque wrench and producing that deflection, which is measured and translated into ft lbs. Yes one degree of deflection is movement, even 1 minute of 1 degree is movement, which is all work. Maybe you should go look up up how a torque wrench works. I still want to watch you apply 300 ft lbs of force to a torque wrench for 15 million years and tell me you are doing no work. You are exerting energy from your body to produce the force to register 300 ft lbs of torque, which is deflection, which is movement, which is work.
Now who gets to drive your car while you are doing this? <img src="gr_images/icons/cool.gif" border="0">
[ February 05, 2002: Message edited by: BigBake ]</p>
02-05-2002, 11:17 AM
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Re: Horsepower vs Torque thread [quote]Originally posted by Dean98TA:
<strong>Your formula is a linearization tailored to fit the data. It is a relatively simple matter to tailor another formula using only torque. It will require "assumptions" of one more parameter, but your formula is also making assumptions, so there is no foul. <img src="gr_images/icons/wink.gif" border="0">
[ February 05, 2002: Message edited by: Dean98TA ]</strong><hr></blockquote>
You are correct, there was an assumption made in my formula in order for it to work and that was RPM.
<strong>Your formula is a linearization tailored to fit the data. It is a relatively simple matter to tailor another formula using only torque. It will require "assumptions" of one more parameter, but your formula is also making assumptions, so there is no foul. <img src="gr_images/icons/wink.gif" border="0">
[ February 05, 2002: Message edited by: Dean98TA ]</strong><hr></blockquote>
You are correct, there was an assumption made in my formula in order for it to work and that was RPM.
02-05-2002, 11:24 AM
#88
Re: Horsepower vs Torque thread [quote]Originally posted by Dean98TA:
<strong>I can't believe you guys are still stuck on semantics! <img src="gr_grin.gif" border="0">
Saying a car won't move if you applied 1 bajillion pound-feet of torque unless there is horspower is backwards. The correct way to describe what is happening in that situation is to say there is no horsepower because the car is not moving. <img src="gr_stretch.gif" border="0">
You simply cannot make horspower without torque and RPMs.
You need both torque and RPMs. Torque is the force. RPM's are the rotational distance. Put them both together and you have work. Do a certain amount of work in a certain amount of time and you have a rate of work being done.
That rate is called Horsepower.
To say torque is more important than HP, or vice-versa, only shows the lack of understanding of the relationship between the two.
It's simple really. Increase torque while keeping RPM's constant, and you will increase HP. Increase RPM's while keeping torque constant and you will increase HP. Increase both torque and RPM's, and you will increase HP even faster.
What's so hard to understand about this? <img src="gr_images/icons/wink.gif" border="0"> </strong><hr></blockquote>
That is the best description of the relation of tq, hp and rpm's that I have read. Excellent response.
<img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
<strong>I can't believe you guys are still stuck on semantics! <img src="gr_grin.gif" border="0">
Saying a car won't move if you applied 1 bajillion pound-feet of torque unless there is horspower is backwards. The correct way to describe what is happening in that situation is to say there is no horsepower because the car is not moving. <img src="gr_stretch.gif" border="0">
You simply cannot make horspower without torque and RPMs.
You need both torque and RPMs. Torque is the force. RPM's are the rotational distance. Put them both together and you have work. Do a certain amount of work in a certain amount of time and you have a rate of work being done.
That rate is called Horsepower.
To say torque is more important than HP, or vice-versa, only shows the lack of understanding of the relationship between the two.
It's simple really. Increase torque while keeping RPM's constant, and you will increase HP. Increase RPM's while keeping torque constant and you will increase HP. Increase both torque and RPM's, and you will increase HP even faster.
What's so hard to understand about this? <img src="gr_images/icons/wink.gif" border="0"> </strong><hr></blockquote>
That is the best description of the relation of tq, hp and rpm's that I have read. Excellent response.
<img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
02-05-2002, 01:39 PM
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Re: Horsepower vs Torque thread [quote]Originally posted by BigBake:
Applied torque to a torque wrench is known as deflection, deflection is movement, so movement is work. You do not know how a torque wrench works! A bolt does not have to turn, to produce work.
<hr></blockquote>
It does if your 'system' is the bolt. If the bolt does not turn, then you have performed no work on the bolt, no matter how many clicks your torque wrench makes. <img src="gr_images/icons/wink.gif" border="0">
If you don't specify what your system is, then you cannot make a generalization like that.
By the same reasoning, when your motor is idling, it is performing work at a certain rate (making HP), but the car is not moving, right?
Most people will choose the car as the 'system', not the motor's internals, and say there is no HP being made because the car is not moving, even though the engine is turning and making some HP.
[ February 05, 2002: Message edited by: Dean98TA ]</p>
Applied torque to a torque wrench is known as deflection, deflection is movement, so movement is work. You do not know how a torque wrench works! A bolt does not have to turn, to produce work.
<hr></blockquote>
It does if your 'system' is the bolt. If the bolt does not turn, then you have performed no work on the bolt, no matter how many clicks your torque wrench makes. <img src="gr_images/icons/wink.gif" border="0">
If you don't specify what your system is, then you cannot make a generalization like that.
By the same reasoning, when your motor is idling, it is performing work at a certain rate (making HP), but the car is not moving, right?
Most people will choose the car as the 'system', not the motor's internals, and say there is no HP being made because the car is not moving, even though the engine is turning and making some HP.
[ February 05, 2002: Message edited by: Dean98TA ]</p>
02-05-2002, 01:40 PM
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Re: Horsepower vs Torque thread [quote]Originally posted by Dean98TA:
<strong>You simply cannot make horspower without torque and RPMs.<hr></blockquote></strong>
I think we have said this 100000 times. And in an internal combustion engine you can not have torque without hp either - or the engine ceases to function.
The point is torque output is IRRELEVANT when determining potential to accelerate. Not what makes a fun street car blah blah blah. Simply determining potential to accelerate requires only a hp.
[quote]It's simple really. Increase torque while keeping RPM's constant, and you will increase HP. Increase RPM's while keeping torque constant and you will increase HP. Increase both torque and RPM's, and you will increase HP even faster.
What's so hard to understand about this?
<hr></blockquote>
Nothing, I think it's what has been said for the entire thready in one form or another. Again, the point we are arguing is that when determining potential to accelerate it doesn't matter what torque I have. Yes, it will be there, as will rpm, but the respective values are irrelevant, HP is what matters (the product of the two).
[quote]Your formula is what engineers call a linearization of what's going on to simplify a mathematical model. It's done all the time, so there's nothing wrong with it, but it is not a mathematical proof.<hr></blockquote>
It's not a proof, but in this context it serves the same point. What I wanted was a mathematical basis for using only torque, weight, and distance to determine potential E.T. I was provided with a wonderful 13.2@105 figure. I am sure you realize that this is B.S. as it's impossible to do without RPM. I simply wanted to see how this figure was arrived at?
[quote]If you are allowed to make assumptions (the averages you mentioned), then I can make the same type of assumptions with vehicle weight, average RPMs, and using just torque figures and arrive at similar conclusions about the ET and MPH. It's not "impossible". Far from it.<hr></blockquote>
And tell me, what do you get at when you combine torque and RPM? You are just getting at horsepower by calculating it indirectly.
It *IS* impossible to do without knowing RPM, which was my claim.
[quote]It is a relatively simple matter to tailor another formula using only torque. It will require "assumptions" of one more parameter<hr></blockquote>
Unacceptable, solve the problem *without* using both torque and rpm. Once you have done that you have HP. You are saying "hey, velocity doesn't matter, I just need to know distance and time" in effect. If you can solve the above problem with only using torque, weight, and distance then I am proven wrong - but you know as well as I that that can not be done.
As for the assumptions - there's no point to not using averages in this context because I don't want to be bogged down by the mathematics or typing the symbols. The formula above is also perfectly derivable using newtonian methods as well as calculus based methodology - think about it for a second. As for the average hp values what point would have been served by me deriving a function for hp and constantly having to integrate that? Not much, except to confuse the issue.
[quote]Applied torque to a torque wrench is known as deflection, deflection is movement, so movement is work. You do not know how a torque wrench works! A bolt does not have to turn, to produce work.<hr></blockquote>
You are just being perverse, correct? Look at this from a system contect. We are talking about how much work is DONE ON THE NUT. If the nut doesn't turn - NONE, ZERO. It's as simple as that. Bending of the torque wrench isn't really relevent to the nut - except that it is a deviation from an ideal system.
[quote]You are correct, there was an assumption made in my formula in order for it to work and that was RPM.<hr></blockquote>
Hmm, so now you mentioned you assumed RPM even though the point of the exercise was to use torque, weight, and distance only.
I am curious, can you tell me what I get when I look at torque at a fixed rpm point, and say, divide it by 5250? It wouldn't be horsepower, would it? You wouldn't be solving for HP indireclty would you?
Yep, you would.
<strong>You simply cannot make horspower without torque and RPMs.<hr></blockquote></strong>
I think we have said this 100000 times. And in an internal combustion engine you can not have torque without hp either - or the engine ceases to function.
The point is torque output is IRRELEVANT when determining potential to accelerate. Not what makes a fun street car blah blah blah. Simply determining potential to accelerate requires only a hp.
[quote]It's simple really. Increase torque while keeping RPM's constant, and you will increase HP. Increase RPM's while keeping torque constant and you will increase HP. Increase both torque and RPM's, and you will increase HP even faster.
What's so hard to understand about this?
<hr></blockquote>
Nothing, I think it's what has been said for the entire thready in one form or another. Again, the point we are arguing is that when determining potential to accelerate it doesn't matter what torque I have. Yes, it will be there, as will rpm, but the respective values are irrelevant, HP is what matters (the product of the two).
[quote]Your formula is what engineers call a linearization of what's going on to simplify a mathematical model. It's done all the time, so there's nothing wrong with it, but it is not a mathematical proof.<hr></blockquote>
It's not a proof, but in this context it serves the same point. What I wanted was a mathematical basis for using only torque, weight, and distance to determine potential E.T. I was provided with a wonderful 13.2@105 figure. I am sure you realize that this is B.S. as it's impossible to do without RPM. I simply wanted to see how this figure was arrived at?
[quote]If you are allowed to make assumptions (the averages you mentioned), then I can make the same type of assumptions with vehicle weight, average RPMs, and using just torque figures and arrive at similar conclusions about the ET and MPH. It's not "impossible". Far from it.<hr></blockquote>
And tell me, what do you get at when you combine torque and RPM? You are just getting at horsepower by calculating it indirectly.
It *IS* impossible to do without knowing RPM, which was my claim.
[quote]It is a relatively simple matter to tailor another formula using only torque. It will require "assumptions" of one more parameter<hr></blockquote>
Unacceptable, solve the problem *without* using both torque and rpm. Once you have done that you have HP. You are saying "hey, velocity doesn't matter, I just need to know distance and time" in effect. If you can solve the above problem with only using torque, weight, and distance then I am proven wrong - but you know as well as I that that can not be done.
As for the assumptions - there's no point to not using averages in this context because I don't want to be bogged down by the mathematics or typing the symbols. The formula above is also perfectly derivable using newtonian methods as well as calculus based methodology - think about it for a second. As for the average hp values what point would have been served by me deriving a function for hp and constantly having to integrate that? Not much, except to confuse the issue.
[quote]Applied torque to a torque wrench is known as deflection, deflection is movement, so movement is work. You do not know how a torque wrench works! A bolt does not have to turn, to produce work.<hr></blockquote>
You are just being perverse, correct? Look at this from a system contect. We are talking about how much work is DONE ON THE NUT. If the nut doesn't turn - NONE, ZERO. It's as simple as that. Bending of the torque wrench isn't really relevent to the nut - except that it is a deviation from an ideal system.
[quote]You are correct, there was an assumption made in my formula in order for it to work and that was RPM.<hr></blockquote>
Hmm, so now you mentioned you assumed RPM even though the point of the exercise was to use torque, weight, and distance only.
I am curious, can you tell me what I get when I look at torque at a fixed rpm point, and say, divide it by 5250? It wouldn't be horsepower, would it? You wouldn't be solving for HP indireclty would you?
Yep, you would.
02-05-2002, 01:56 PM
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Re: Horsepower vs Torque thread [quote]As for the assumptions - there's no point to not using averages in this context because I don't want to be bogged down by the mathematics or typing the symbols. The formula above is also perfectly derivable using newtonian methods as well as calculus based methodology - think about it for a second. As for the average hp values what point would have been served by me deriving a function for hp and constantly having to integrate that? Not much, except to confuse the issue.<hr></blockquote>
You are trying to split a hair here.
By saying only your assumptions are valid is kind of silly, no?
I'm saying my assumption of RPM's is just as valid because I'm constraining the RPM range to that of a typical LS1 motor. I'm performing a linearization too! <img src="gr_stretch.gif" border="0">
By doing that, I can derive a formula for an LS1 that is just as accurate as yours, because even your formula is at best, only an approximation.
IOW, it's close, and that's all that matters. Mine can be just as close. <img src="gr_stretch.gif" border="0">
You are trying to split a hair here.
By saying only your assumptions are valid is kind of silly, no?
I'm saying my assumption of RPM's is just as valid because I'm constraining the RPM range to that of a typical LS1 motor. I'm performing a linearization too! <img src="gr_stretch.gif" border="0">
By doing that, I can derive a formula for an LS1 that is just as accurate as yours, because even your formula is at best, only an approximation.
IOW, it's close, and that's all that matters. Mine can be just as close. <img src="gr_stretch.gif" border="0">
02-05-2002, 01:59 PM
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Re: Horsepower vs Torque thread Dean, you are just being perverse to, and you know it <img src="gr_stretch.gif" border="0">
The point is torque and rpm is horsepower. Again, that's like you saying "Hey, I don't need velocity, I just need distance and time".
It's about exactly the same thing
That's the reason I said you can't use RPM - because, again, if you use RPM and torque you are just getting at HP. Which proves my point, that HP is all that matters. Sure, it is composed of torque and rpm, but what those values are just don't matter from a potential to accelerate perspective, only the final product.
Chris
The point is torque and rpm is horsepower. Again, that's like you saying "Hey, I don't need velocity, I just need distance and time".
It's about exactly the same thing
That's the reason I said you can't use RPM - because, again, if you use RPM and torque you are just getting at HP. Which proves my point, that HP is all that matters. Sure, it is composed of torque and rpm, but what those values are just don't matter from a potential to accelerate perspective, only the final product.
Chris
02-05-2002, 02:30 PM
#93
Re: Horsepower vs Torque thread [quote]Originally posted by ChrisB:
<strong>The point is torque and rpm is horsepower. Again, that's like you saying "Hey, I don't need velocity, I just need distance and time".
Chris</strong><hr></blockquote>
distance/time is an average velocity over that time, not the magnitude of the actual instantaneous vector. Another linearization of a function...
PHTPHTPHT!!! <img src="gr_tounge.gif" border="0">
You guys are just going around in circles <img src="gr_grin.gif" border="0">
HP is what matters anyways... otherwise a Cummins TD would be the winningest drag motor of all time <img src="gr_images/icons/wink.gif" border="0">
If you have the horsepower curve and gear ratios for a vehicle, and can make some assumptions about the rather unpredictable and turbulent first 60ft, you can plot the position of the car over time. If you want to do that with the tq curve, you have to have RPM, which means you have to have the HP.
Why am I adding/fueling this 4 page thing? <img src="gr_images/icons/wink.gif" border="0">
chris
<strong>The point is torque and rpm is horsepower. Again, that's like you saying "Hey, I don't need velocity, I just need distance and time".
Chris</strong><hr></blockquote>
distance/time is an average velocity over that time, not the magnitude of the actual instantaneous vector. Another linearization of a function...
PHTPHTPHT!!! <img src="gr_tounge.gif" border="0">
You guys are just going around in circles <img src="gr_grin.gif" border="0">
HP is what matters anyways... otherwise a Cummins TD would be the winningest drag motor of all time <img src="gr_images/icons/wink.gif" border="0">
If you have the horsepower curve and gear ratios for a vehicle, and can make some assumptions about the rather unpredictable and turbulent first 60ft, you can plot the position of the car over time. If you want to do that with the tq curve, you have to have RPM, which means you have to have the HP.
Why am I adding/fueling this 4 page thing? <img src="gr_images/icons/wink.gif" border="0">
chris
02-05-2002, 10:24 PM
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Re: Horsepower vs Torque thread [quote]
Torque is NOT WORK. Torque is a rotational Force.
Work is defined as Force x distance.
Torque is the cross product of Force and your Lever arm (d, or distance from point of application of force).
So we have Tq = R*F sine (theta)
R = lenght of lever arm from point of application of force
F = Force applied (newtons, etc)
Sine (theta) is the angle of the application of the force, and we can assume the angle to be 90 degrees so sine of 90 degrees
is equal to 1.
Thus, Tq = R*F
There is no distance moved in this equation. You only have the radius of the lever arm and the force applied. Therefore, no
work is done although you may be sweating like a hog, you did NO work.
You have to move something a certain distance for ANY work to be done. If try to lift a chair bolted to the floor you do no
physical work, except burn some calories. Now if you lift a 10lb chair 1 foot off the ground, you have done 10 ft*lb's of work. <hr></blockquote>
do you need to look at a dictionary Nasty? Yes, torque IS work because a torque always assumes that there is displacement (in this case rotation). IF there is no movement then all you have is a force.... a moment since it is rotational. You can have a force with no motion (go push on a wall), but you will not do work on it. Only work is done when the wall falls down. The analogy to a nut and torque wrench shows this example very clearly. If the nut is moving then you are applying a torque, but as soon as it stops it is a moment.. not "zero work". Horsepower is a rate of doing work... it is not work itself. It's the whole keypoint of "rate" that makes hp the determing factor in how fast you are going to accelerate.
ChrisB is 100% right that you can't determine acceleration over a given time given only a torque value... only instantaneous acceleration. Obviously you can't have one without the other, but one is a rate (power) and one isn't, so that's all the explanation you need.
John
Torque is NOT WORK. Torque is a rotational Force.
Work is defined as Force x distance.
Torque is the cross product of Force and your Lever arm (d, or distance from point of application of force).
So we have Tq = R*F sine (theta)
R = lenght of lever arm from point of application of force
F = Force applied (newtons, etc)
Sine (theta) is the angle of the application of the force, and we can assume the angle to be 90 degrees so sine of 90 degrees
is equal to 1.
Thus, Tq = R*F
There is no distance moved in this equation. You only have the radius of the lever arm and the force applied. Therefore, no
work is done although you may be sweating like a hog, you did NO work.
You have to move something a certain distance for ANY work to be done. If try to lift a chair bolted to the floor you do no
physical work, except burn some calories. Now if you lift a 10lb chair 1 foot off the ground, you have done 10 ft*lb's of work. <hr></blockquote>
do you need to look at a dictionary Nasty? Yes, torque IS work because a torque always assumes that there is displacement (in this case rotation). IF there is no movement then all you have is a force.... a moment since it is rotational. You can have a force with no motion (go push on a wall), but you will not do work on it. Only work is done when the wall falls down. The analogy to a nut and torque wrench shows this example very clearly. If the nut is moving then you are applying a torque, but as soon as it stops it is a moment.. not "zero work". Horsepower is a rate of doing work... it is not work itself. It's the whole keypoint of "rate" that makes hp the determing factor in how fast you are going to accelerate.
ChrisB is 100% right that you can't determine acceleration over a given time given only a torque value... only instantaneous acceleration. Obviously you can't have one without the other, but one is a rate (power) and one isn't, so that's all the explanation you need.
John
02-06-2002, 12:06 AM
#95
TECH Senior Member
Re: Horsepower vs Torque thread I am quite aware of how a TQ wrench works. <img src="images/icons/rolleyes.gif" border="0"> I mean after the deflection is through with. (Did I not specify IF NOTHING MOVES???) It's called, speaking hypothetically. Might as well go ahead and point out that there is going to be more than just a little deflection if you apply that much TQ to a TQ wrench! LOL! <img src="graemlins/gr_jest.gif" border="0" alt="[jester]" />
Deflection or not, I see you got my point since you pointed out that that deflection was indeed movement and that the movement constituted work (or HP.) That was my whole point. You have to have movement for work to take place.
Deflection or not, I see you got my point since you pointed out that that deflection was indeed movement and that the movement constituted work (or HP.) That was my whole point. You have to have movement for work to take place.
02-06-2002, 01:29 AM
#96
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Re: Horsepower vs Torque thread [quote]Originally posted by ChrisB:
<strong> I repeat my challenge, if torque is what matters please tell me what the estimate ET/MPH would be for a car, say 3000lbs, making an average of 300 ft-lbs of torque down the track.
Chris Bennight</strong><hr></blockquote>
Yep I am pretty sure that this is your own words right here. At no point did you state that I could only use torque and weight. Maybe you need a class in writing and interpretation. As far as RPM being used, well that is simple, provided that we are on a site that has pages of dyno sheets of LS1's.
You are just being perverse, correct? Look at this from a system contect. We are talking about how much work is DONE ON THE NUT. If the nut doesn't turn - NONE, ZERO. It's as simple as that. Bending of the torque wrench isn't really relevent to the nut - except that it is a deviation from an ideal system.
Once again no one said it had to be the end result, and it does not have to be the end result. It still requires force applied, to get a reading on a torque wrench which is work. I don't care what your ideal system is, because I use this everyday in my job. By the way, a click type torque wrench is not as accurate as a dial or digital. Try using a dial or digital sometime and you will see what I am talking about. This same principle is used to give aircraft torque readings. We measure deflection from a fixed magnet on the drive shaft and use a electromagnetic pick up sensor to relay the siganl to an indicator. So it an applied ideal that is patented, may not be your ideal but apparently someone else thinks the same way I do, no matter how perverse you may think. Plus it is not theory, it is applied science, not something quoted out of a book, and then regurgitated by someone else, to make them look like they know what they are talking about.
<strong> I repeat my challenge, if torque is what matters please tell me what the estimate ET/MPH would be for a car, say 3000lbs, making an average of 300 ft-lbs of torque down the track.
Chris Bennight</strong><hr></blockquote>
Yep I am pretty sure that this is your own words right here. At no point did you state that I could only use torque and weight. Maybe you need a class in writing and interpretation. As far as RPM being used, well that is simple, provided that we are on a site that has pages of dyno sheets of LS1's.
You are just being perverse, correct? Look at this from a system contect. We are talking about how much work is DONE ON THE NUT. If the nut doesn't turn - NONE, ZERO. It's as simple as that. Bending of the torque wrench isn't really relevent to the nut - except that it is a deviation from an ideal system.
Once again no one said it had to be the end result, and it does not have to be the end result. It still requires force applied, to get a reading on a torque wrench which is work. I don't care what your ideal system is, because I use this everyday in my job. By the way, a click type torque wrench is not as accurate as a dial or digital. Try using a dial or digital sometime and you will see what I am talking about. This same principle is used to give aircraft torque readings. We measure deflection from a fixed magnet on the drive shaft and use a electromagnetic pick up sensor to relay the siganl to an indicator. So it an applied ideal that is patented, may not be your ideal but apparently someone else thinks the same way I do, no matter how perverse you may think. Plus it is not theory, it is applied science, not something quoted out of a book, and then regurgitated by someone else, to make them look like they know what they are talking about.
02-06-2002, 09:52 AM
#97
Re: Horsepower vs Torque thread [quote]Originally posted by ramairJP:
<strong>
do you need to look at a dictionary Nasty? Yes, torque IS work because a torque always assumes that there is displacement (in this case rotation). IF there is no movement then all you have is a force.... a moment since it is rotational. You can have a force with no motion (go push on a wall), but you will not do work on it. Only work is done when the wall falls down. The analogy to a nut and torque wrench shows this example very clearly. If the nut is moving then you are applying a torque, but as soon as it stops it is a moment.. not "zero work". Horsepower is a rate of doing work... it is not work itself. It's the whole keypoint of "rate" that makes hp the determing factor in how fast you are going to accelerate.
John</strong><hr></blockquote>
All of the physics professors I have had have told me that Torque is NOT work. All of my collegiate physics book tell me this as well.
Once again, tq = Radius (lenght of moment arm) x F (Force) sine (theta)
To do work the force (or Torque) you apply must cause movement in some direction whether it be linear, angular, etc. Until the lever arm MOVES any distance there is NO WORK DONE.
All I am saying is that torque by itself is NOT WORK but a force!
Here:
Q: What is torque?
A: Torque is a physical vector quantity characteristic for an object in rotational motion around a certain given axis. By definition torque () is the cross product between the vector of position (r) of the point where a force is applied ( from an origin considered to be on the axis of rotation) and the applied force (F) ( = r x F). According to the definition of the cross (or vector) product, the magnitude of the torque is equal to the magnitude of r times the magnitude of F multiplied by sine of the angle () between r and F ( = r F sin ). In this expression for magnitude of the torque, the product (r sin ) is equal to the magnitude of the distance (d) between the axis of rotation and the "line of action" of the force (F) (r sin = d). This distance (d) is called "arm of the force." Now, the torque can be expressed as = Fd (torque is equal to force multiplied by the arm of the force.) Intuitively, torque can be interpreted as "force with a twist" since it results in rotation of the object on which the force is applied.
Work exists only in transitional form. Work is equal to the product of the force used to move something and the distance that it is moved. If there is no movement there is no work done.
W = F D
W Work
F Force
D Distance
And no, I do not need a dictionary to know what torque is, and to solve this, I went to www.dictionary.com and looked up torque for you, here it is:
torque1 (tôrk)
n.
The moment of a force; the measure of a force's tendency to produce torsion and rotation about an axis, equal to the vector product of the radius vector from the axis of rotation to the point of application of the force and the force vector.
A turning or twisting force.
Torque is a FORCE. Only when this FORCE causes motion is there WORK! Plain and simple.
BTW, here's the definition of work in the physics realm:
In physics, work is defined as a force acting upon an object to cause a displacement. There are three key words in this definition - force, displacement, and cause. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause the displacement.
From:http://www.glenbrook.k12.il.us/gbssc...rgy/u5l1a.html
<img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
[ February 06, 2002: Message edited by: NastyC5 ]</p>
<strong>
do you need to look at a dictionary Nasty? Yes, torque IS work because a torque always assumes that there is displacement (in this case rotation). IF there is no movement then all you have is a force.... a moment since it is rotational. You can have a force with no motion (go push on a wall), but you will not do work on it. Only work is done when the wall falls down. The analogy to a nut and torque wrench shows this example very clearly. If the nut is moving then you are applying a torque, but as soon as it stops it is a moment.. not "zero work". Horsepower is a rate of doing work... it is not work itself. It's the whole keypoint of "rate" that makes hp the determing factor in how fast you are going to accelerate.
John</strong><hr></blockquote>
All of the physics professors I have had have told me that Torque is NOT work. All of my collegiate physics book tell me this as well.
Once again, tq = Radius (lenght of moment arm) x F (Force) sine (theta)
To do work the force (or Torque) you apply must cause movement in some direction whether it be linear, angular, etc. Until the lever arm MOVES any distance there is NO WORK DONE.
All I am saying is that torque by itself is NOT WORK but a force!
Here:
Q: What is torque?
A: Torque is a physical vector quantity characteristic for an object in rotational motion around a certain given axis. By definition torque () is the cross product between the vector of position (r) of the point where a force is applied ( from an origin considered to be on the axis of rotation) and the applied force (F) ( = r x F). According to the definition of the cross (or vector) product, the magnitude of the torque is equal to the magnitude of r times the magnitude of F multiplied by sine of the angle () between r and F ( = r F sin ). In this expression for magnitude of the torque, the product (r sin ) is equal to the magnitude of the distance (d) between the axis of rotation and the "line of action" of the force (F) (r sin = d). This distance (d) is called "arm of the force." Now, the torque can be expressed as = Fd (torque is equal to force multiplied by the arm of the force.) Intuitively, torque can be interpreted as "force with a twist" since it results in rotation of the object on which the force is applied.
Work exists only in transitional form. Work is equal to the product of the force used to move something and the distance that it is moved. If there is no movement there is no work done.
W = F D
W Work
F Force
D Distance
And no, I do not need a dictionary to know what torque is, and to solve this, I went to www.dictionary.com and looked up torque for you, here it is:
torque1 (tôrk)
n.
The moment of a force; the measure of a force's tendency to produce torsion and rotation about an axis, equal to the vector product of the radius vector from the axis of rotation to the point of application of the force and the force vector.
A turning or twisting force.
Torque is a FORCE. Only when this FORCE causes motion is there WORK! Plain and simple.
BTW, here's the definition of work in the physics realm:
In physics, work is defined as a force acting upon an object to cause a displacement. There are three key words in this definition - force, displacement, and cause. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause the displacement.
From:http://www.glenbrook.k12.il.us/gbssc...rgy/u5l1a.html
<img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
[ February 06, 2002: Message edited by: NastyC5 ]</p>
02-06-2002, 10:11 AM
#98
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Re: Horsepower vs Torque thread <img src="graemlins/gr_jest.gif" border="0" alt="[jester]" /> -------> RamairJp got told by <img src="graemlins/gr_hail.gif" border="0" alt="[hail]" /> Nasty C5
RamairJp needs a dictionary <img src="graemlins/gr_judge.gif" border="0" alt="[judgement]" />
[ February 06, 2002: Message edited by: 2000 ws6 ]</p>
RamairJp needs a dictionary <img src="graemlins/gr_judge.gif" border="0" alt="[judgement]" />
[ February 06, 2002: Message edited by: 2000 ws6 ]</p>
02-06-2002, 10:18 AM
#99
Re: Horsepower vs Torque thread [quote]Originally posted by ramairJP:
<strong>
do you need to look at a dictionary Nasty? Yes, torque IS work because a torque always assumes that there is displacement (in this case rotation). </strong><hr></blockquote>
If this is true then why do engineers who build stable and solid structures use the physics of Statics to sum all of the torques (forces) to make sure that they equal zero so that you don't have bridges falling over and building collapsing. I distinctly remember doing MANY lab experiments, homework problem, exam questions based solely on statics where you had to find the sum of ALL the torques displaced by FIXED objects. (by fixed, they DON'T move). Damn I wish I had my physics book so I could scan a simple statics problem to show that torque does NOT assume displacement! If you ALWAYS assumed displacement then there would be NO statics and the world of physics would rely solely on dynamics.
<img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
[ February 06, 2002: Message edited by: NastyC5 ]</p>
<strong>
do you need to look at a dictionary Nasty? Yes, torque IS work because a torque always assumes that there is displacement (in this case rotation). </strong><hr></blockquote>
If this is true then why do engineers who build stable and solid structures use the physics of Statics to sum all of the torques (forces) to make sure that they equal zero so that you don't have bridges falling over and building collapsing. I distinctly remember doing MANY lab experiments, homework problem, exam questions based solely on statics where you had to find the sum of ALL the torques displaced by FIXED objects. (by fixed, they DON'T move). Damn I wish I had my physics book so I could scan a simple statics problem to show that torque does NOT assume displacement! If you ALWAYS assumed displacement then there would be NO statics and the world of physics would rely solely on dynamics.
<img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
[ February 06, 2002: Message edited by: NastyC5 ]</p>