## Impulse/force in pounds for the time frame

 Quote by sophiecentaur Wayne. Would you expect to conversation about tennis if you insisted on using the language of football? This is effectively what you are trying to do with your arrogant misuse of the vocabulary. Learn the right terms or go to a less rigorous forum. You may get a (wrong) answer that will make you happy.
I am sorry that my wording sounds arrogant, it’s not meant to be, I am trying my best. But if you “please” tell me what you do not understand, and I will explain it more. I don’t want a wrong answer.

Ok sophiecentaur let me try again.

1,
I imagine you know what am EMG machine is, but just in case, it’s a machine that measures the electrical signals in the muscles. I attached the pads to my muscles and did several tests, all the tests as you see in my earlier posts and a video, showed that there “was more” average muscle force/strength, muscle activity when the weight was moved very fast to very slow. As a physicist, I thought that would intrigue you that it a real life practical experiment showed you was wrong, and that you might want to find out why.

2,
When anybody moves a weight faster, but in this case is using 80% or the persons 1RM {Repetition Maximum or the most weight a person can lift up for a full repetition one time} “you” are saying that the person does not use more of the total or overall force they have, {and we all do only have a limited force/strength to use, and when using 80% its about 15 seconds or more} when moving it faster, am I right there ??? If so, as this is what you’re saying, how when we only have a limited amount of force to use, does the person moving the 80% as fast as he can, hit muscular failure nearly twice as fast ??? Or in other words the person moving the fastest, moves the weight faster, for more distance in the 50% less the time frame then the slow, thus his limited temporary force they have has been used up faster, but you are saying it’s not ??? But then again you do say that the energy is used up faster, but not the force, please, this seems a contradiction to me. As if you’re using more energy, you “must” be using more or a higher amount of force that you have, right ??? If not, why would you use more energy if you not using more of the limited force, or a higher force, of the limited force ???

If that’s got a bit complicated, and it has, let me explain a little different.

Clone 1 and 2 can lift up 100 pounds in 4 seconds, and lower the 100 pounds in 4 seconds 4 repetitions/times = 32 seconds, then they have hit muscular failure. {meaning they cannot lift the weight again, until the force, in this case the muscles have got they temporary force back, as the muscles need to replenish they energy supplies}

However, if Clone 1 and 2 lift up 100 pounds in 1 second, and lower the 100 pounds in 1 second, they “will” hit muscular failure far far far faster, in roughly 8 repetition or 16 seconds 4 times.

Does not this mean that when the Clones were lifting faster, they were using up more of the temporary total/over force they had, and faster ??? You saeem to be saying no ??? So why do they fail at diffrent times lifting the weight at diffrent speeds ???

3,
Also, you seem you be saying that it takes the same total/overall force/strength to move a weight a 1000mm and only a 166mm. If the faster accelerated the weight for just 60% 600mm, that would mean you’re saying that it takes the same force to accelerate a weight a 600mm and to move it at a constant velocity only 166mm. To me that’s saying F = ma is wrong. Also, power is the rate at which energy is transferred, power is the rate at which this work is performed, thus I use more force doing more work and need more energy to do this.

4,
Do you, agree, that the faster you move something with a force the more or the faster the energy is used. I think you will say yes, as we cover this in another debate, to which Douglas did admit he was wrong on that one.

5,
Can you have more power with the same amount of force ???

Wayne

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 Quote by waynexk8 On a physics site, this is not an answer; Wayne
Actually, it's a very reasonable answer.

I think it's clear that you don't want a Physics site. What you want is a 'Chew the Fat site' in which no-one really knows what they're talking about but everyone has a good time playing with 'Science Sounding Words'. I'm afraid that PF is not like that. Take a look at the majority of other threads and see how people 'behave themselves' correctly, scientifically.

Like I said earlier, it's GIGO.

 Recognitions: Gold Member Science Advisor @Wayne I just read your long post. Your insistence on using terms wrongly can only be regarded as arrogant - when you have been told so many times what the right terms are. You equate force / strength / energy at every opportunity which makes the accompanying reams of stuff meaningless. What's the point in saying that you're sorry if you continue to say the same old rubbish. You seem to want to pick holes in the explanations given by Douglass and others when they / we have no real idea what question you are actually asking. If you say that reading a Physics text book is beyond you then how could you think that you would understand and be qualified to argue with what you read here? I should just turn on your EMG /ESP /SPQR machine and enjoy reading the figures it shows you. That's what you paid your money for. Aim at making them higher (or lower) and see if you feel fitter / stronger as a result. Enjoy things at that level. No one will argue with you or get exasperated.

 Quote by sophiecentaur I should just turn on your EMG /ESP /SPQR machine and enjoy reading the figures it shows you. That's what you paid your money for. Aim at making them higher (or lower) and see if you feel fitter / stronger as a result. Enjoy things at that level. No one will argue with you or get exasperated.
I stopped reading Wayne's posts.He has created a world where "you use force from the temporary available force" whatever that could possibly mean.

As for his EMG machine,he has stated that it doesn't give figures.It only gives the Root Mean Square values of the recorded electrical signal.So the numbers that his machines gives are the 70% of the peak recorded values.
Obviously with fast lifting the peaks of the fluctuated force are much higher than slow lifting so the Root Mean Square will also be higher.

 Quote by sophiecentaur An EMG may not be Waynephysics but, without reading about what it claims to do, I have to assume it is EMGPhysics which may not be real Physics at all. It wouldn't be the only thing that's been sold on dodgy Science now, would it? Do you have a link about it?
Hi there sophiecentaur,

The Electromyography, EMG machine has been around for some time, in the medical Would it’s as well know as a Kidney machine, but its far far far more widely used, and used all Universities and medical sports science facility’s, its “NO” gimmick, it “DOES” measure the electrical signals that the muscles give out while at rest and exercise. It’s “ALWAYS” used in the studies of Kinology and Biomechanics.

Here is the one I bought.

http://www.tensmachines.co.uk/NeuroT...nal_p_133.html

So please, as this gives out a reading of the fast average far higher every time, on its set time, could you please, or should I say hopefully comment more on why the physics equations are wrong.

Please for one moment could we just pretend we all just meet and you just heard of the debate. As too me, if I you or anyone else lifts say 80% of the 1RM, 6 times up and down say in the bench press, in the same time frame as lifting the weight 1 time up and down, it just seems that without even thinking about it, that you just have to use more force/strength to lift it up and down 6 times.

1,
More Power, the rate at which energy is transferred/used, but we all agree on this.
2,
More Work, but we all agree on this. As the fast has moved the weight 1000mm to the slow 166mm, and accelerated the weight 600mm. Since work is defined as a force acting through a distance, the fast as used more work/force acting though a distance ???

3,
You always fail faster about 50% faster in the faster repetitions, so if you fail faster, you “HAVE” used up your temporary force/strength, as you hit muscular failure faster thus you cannot lift the weight anymore. To me, if both Clones started the fast and slow lifting at the same time, as the slow Clone are still lifting the weights when the fast Clone has hit muscular failure and unable to lift the weight anymore, this “is/seems irrefutable, or categorically right to me, and I am not trying to sound smug or anything here, but if the slow Clone is still moving the weight, then the fast Clone “has” used up more overall or the total force/strength they had faster, if you see my point, please do you see what I am saying here ???

4,
EMG state you use more muscle activity when moving anything faster.

5,
Can you have more power with the same amount of force ???

 Quote by sophiecentaur You say you would "rather talk Physics" but you seldom actually do. That's my point. You talk your own home-brewed version which is not compatible with the real stuff.
I am trying my best, and have come here to learn the talk of physics, however, still you have not said what you dont understand what I am saying.

Thank you again for your time.

Wayne

 Recognitions: Gold Member Science Advisor You say you have come to "talk Physics" but you refuse to do just that. You have your own brand of vocabulary, a lot of which has nothing to do with Physics. I'm sorry but several of us have told, on many occasions, you that what you say is not understandable because you use meaningless combinations of a random set of words that you haven't defined. That machine of yours is just telling you something about muscle activity and, hence, about the Energy that your Muscles are transferring. It tells you nothing about the amount of (and here I am using the term in the correct way) Work Done on the weights you are shifting. You want there to be a definite relationship. There is no reason why there should be, in general. It's often quite clear when you're doing more useful work and less work work - for instance, when running uphill with a pack and the EMG would probably agree. But when you are lifting weights, holding them and lowering them, there can be no useful connection. Why do you insist that you want one? You won't accept that this is just not Physics. Proper Physics equations will not be "wrong" when applied to the right situation. This is just not one of those situations. There are questions in the above list that you could answer for yourself just by looking at wikipedia and there are some which no one could answer because they don't relate to Physics.

 Quote by sophiecentaur Actually, it's a very reasonable answer. I think it's clear that you don't want a Physics site. What you want is a 'Chew the Fat site' in which no-one really knows what they're talking about but everyone has a good time playing with 'Science Sounding Words'. I'm afraid that PF is not like that.
No I definitely do not want that, I only look for the truth, that why we came here.

 Quote by sophiecentaur Take a look at the majority of other threads and see how people 'behave themselves' correctly, scientifically. Like I said earlier, it's GIGO.
But I am behaving myself, I don’t know what you mean there, I have been polite all along, all I said was a straight forward scientific question, AND then put the reasons with proof, evince and facts why I think the fast uses more overall or total force/strength, like in 1 to 4 above, here is the question again, I don’t understand what’s wrong with it, if you don’t understand or think I ask it the wrong way, I would please like to know. As I do not want to get on anyone nerves, and as you say, I don’t want to piss you off. I just cont get why all this other stuff other than the debate is going on, ok, my Grammar is not that good, but surely you don’t hold that against me, as all spelling is fine.

Weight used roughly 80% of the persons 1RM. {Repitition Maxumun, or the most weight you can lift up once} Lift/exersice, bench press, {but it could be any exersice} 20 inch concentric and 20 inch eccentric.

Fast, 6 reps at .5/.5 = 6 seconds = 240 inch, or/and 24 reps at .5/.5 = 24 seconds 5760 inch.

Slow, 1 rep at 3/3 = 6 seconds = 40 inch, or/and 4 reps at 3/3 = 24 seconds = 160 inch.

Question,
As you only have a limited {as in time} temporary amount of force/strength available to lift 80% at both velocities, as you force/strength will temporary run out, which velocity will use the most overall or total force.

My debate/defence for the faster repetitions is as follows.

1,
More Power, the rate at which energy is transferred/used, but we all agree on this.
2,
More Work, but we all agree on this. As the fast has moved the weight 1000mm to the slow 166mm, and accelerated the weight 600mm. Since work is defined as a force acting through a distance, the fast as used more work/force acting though a distance ???

3,
You always fail faster about 50% faster in the faster repetitions, so if you fail faster, you “HAVE” used up your temporary force/strength, as you hit muscular failure faster thus you cannot lift the weight anymore. To me, if both Clones started the fast and slow lifting at the same time, as the slow Clone are still lifting the weights when the fast Clone has hit muscular failure and unable to lift the weight anymore, this “is/seems irrefutable, or categorically right to me, and I am not trying to sound smug or anything here, but if the slow Clone is still moving the weight, then the fast Clone “has” used up more overall or the total force/strength they had faster, if you see my point, please do you see what I am saying here ???

4,
EMG state you use more muscle activity when moving anything faster.

Wayne

 Quote by sophiecentaur You say you have come to "talk Physics" but you refuse to do just that. You have your own brand of vocabulary, a lot of which has nothing to do with Physics. I'm sorry but several of us have told, on many occasions, you that what you say is not understandable because you use meaningless combinations of a random set of words that you haven't defined.
Is not force a push or pull ??? Is not distance inches or other ??? Is time, as in seconds or other ??? “Please” I do not understand what you don’t understand, or what I am asking wrong, please could you either tell me what you don’t understand, or how I am saying it wrong ???

 Quote by sophiecentaur That machine of yours is just telling you something about muscle activity and, hence, about the Energy that you’re Muscles are transferring.
This machine is “NOT” telling me the energy I am using, its telling me the muscle “activity” as in Newton’s used, the machine measures this in μV. Do you know what I force plate is, it basically does the same thing. Electromyography (EMG) is a diagnostic procedure to assess the health of muscles and the nerve cells that control them (motor neurons).
Motor neurons transmit electrical signals that cause muscles to contract. An EMG translates these signals into graphs, sounds or numerical values that a specialist interprets.
An EMG uses tiny devices called electrodes to transmit or detect electrical signals. During a needle EMG, a needle electrode inserted directly into a muscle records the electrical activity in that muscle. A nerve conduction study, another part of an EMG, uses surface electrodes — electrodes taped to the skin — to measure the speed and strength of signals travelling between two or more points. EMG results can reveal nerve dysfunction, muscle dysfunction or problems with nerve-to-muscle signal transmission. An electromyography detects the electrical potential generated by muscle cells when these cells are electrically or neurologically activated. The signals can be analyzed to detect medical abnormalities, activation level, recruitment order or to analyze the biomechanics of human or animal movement.

http://www.nlm.nih.gov/medlineplus/e...cle/003929.htm

Please sophiecentaur, we need to clear this up first, the EMG reads up muscle activity, not the calories you’re using.

 Quote by sophiecentaur It tells you nothing about the amount of (and here I am using the term in the correct way) Work Done on the weights you are shifting.
Yes is does, and this is a well known fact, as if someone is thought to have muscle atrophy, or disuse atrophy, is defined as a decrease in the mass of the muscle; it can be a partial or complete wasting away of muscle, these machines are used.

 Quote by sophiecentaur You want there to be a definite relationship. There is no reason why there should be, in general. It's often quite clear when you're doing more useful work and less work work - for instance, when running uphill with a pack and the EMG would probably agree. But when you are lifting weights, holding them and lowering them, there can be no useful connection. Why do you insist that you want one?
Right now I am maybe understanding you here. As I think of when I lift a weight up and down as strength used, and physics calls this the force used, as force is a push or pull, so that’s why I said force/strength. However are you saying I have to call force/strength work ??? But I thought work is the force times the distance through which it acts, and if a constant force pushes on a object that moves in the direction of the force, then the work done by this force, so the force is doing the work, and the force in this case in the strength of my muscles.

 Quote by sophiecentaur You won't accept that this is just not Physics. Proper Physics equations will not be "wrong" when applied to the right situation.
Very true, but have all the variables been added in, I don’t think so, please read this, look at this from 5.00 min, it states I am right.

Fast
P = 695
F = 579
V = 192

Slow
P = 649
F = 546
V = 161

Please also read chapter 4, just the first 2 pages, it says like I have been trying to say all along, these forces that I talk about cannot be easily equated with physics.

http://www.findphysio.com/E-books/Bi...20Exercise.pdf

 Quote by sophiecentaur This is just not one of those situations.
I think it is, as how do you explain I fail faster in the faster repetitions, thus I “HAVE” used up my force faster than the slow ???

 Quote by sophiecentaur There are questions in the above list that you could answer for yourself just by looking at wikipedia and there are some which no one could answer because they don't relate to Physics.
I have tried to learnt physics a little, this may not mean much to you, but I can work out the power myself, see below, but force is far harder.

To determine the force we will need to figure out what the weight of the barbell is (W = mg = 91 kg x 9.81 m/s? = 892 kg.m/s? or 892 N). Now, if work is equal to Force x distance then, U = 892 N x 1.85 meter = 1650 Nm.

Power, takes time into consideration. If for example, it took .5 seconds to complete the concentric lift, then the power generated is 1650 J divided 1.7 s = 3300 J/s.

If it took 2 seconds to complete the concentric lift, then the power generated is 1650 J divided 2s = 825 J/s.

power = force {strength} x velocity. The force is greater if the SPEED is increasing. If the speed is increasing then the weight is accelerating.

Again, the force generated by the muscles is given by the following: F=mg + ma. The first term on the right (mg) is the load the gravitational contribution. The second term on the right (ma) is the contribution due to the acceleration.

If the speed is constant then a=0 and F=mg...equal to the load. If the speed is increasing, then a is not zero and F=mg + ma.

This is Newton's 2nd Law. It cannot be refuted. At least not in this Universe. In the equation F=mg + ma the speed is irrelevant in the first term on the right (mg=load). But it is not irrelevant in the second term (ma). If the speed is increasing, then there is a non-zero acceleration and a=v/t. A CONSTANT acceleration results in a force. This force is added to the load (mg). Acceleration is a change in SPEED.

Wayne

 Quote by waynexk8 This is Newton's 2nd Law. It cannot be refuted. At least not in this Universe. In the equation F=mg + ma the speed is irrelevant in the first term on the right (mg=load). But it is not irrelevant in the second term (ma). If the speed is increasing, then there is a non-zero acceleration and a=v/t. A CONSTANT acceleration results in a force. This force is added to the load (mg). Acceleration is a change in SPEED. Wayne
Great!For the first time you used some physics!

So what's the change in SPEED when you start and end at rest as it's done when you lift a weight?

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 Quote by waynexk8 But I am behaving myself, I don’t know what you mean there, I have been polite all along, all I said was a straight forward scientific question, AND then put the reasons with proof, evince and facts why I think the fast uses more overall or total force/strength, like in 1 to 4 above, here is the question again, I don’t understand what’s wrong with it, if you don’t understand or think I ask it the wrong way, Wayne
Yes, you are being perfectly polite, which is why we continue to converse with you. However, your initial question was not complete and was not asked in Scientific terms. That was the "behaviour" I was referring to.

"But what would be the impulse/force on/from the components/parts if the weight was lowered at the above vilocity, and for how long in 10ths or whatever in time would that higher force have to be untill the normal acceleration forces of the lift at rest."

Impulse and force are two different things. That's why two different words are used in Physics.
Likewise, for Force and Strength. So you ask about the relationship between one, non specific quantity and another, non-specific quantity. Is that scientific?

You claim that your machine tells you the force involved (in N) but then say that it reads electrical activity in μV. When you 'tense up' your arm, there is no net force at all (it stays still, in its original position) but there is loads of muscle activity, as your machine would show, but the antagonistic muscles are producing equal and opposite force. So there's no direct connection between muscle activity and force produced. That is unless you have electrodes on every muscle group and the machine can do some complicated 'addition' of the effects of all the muscles.

You are still after some relationship between that muscle activity and the measurable work done on a weight when lifting it. But if it's possible to have loads of muscle activity and Zero work done, then there clearly is not one. Can you not accept that?
There is really no more to be said on the topic (except for another acre of figures about rep rates and pounds lifted).

I can only suggest that you approach the manufacturers of your machine and ask them for their opinion. They may well be more prepared to speak you language as it is in their interest to sell as many of those machines as they can. I think they will tell you that the machine gives a good indication of how much energy the muscles are transferring and / or the forces. I have no problem with that (the neurological application of the machine seem very worth while). They may even launch into some link between that and the mechanical work done. That will make you happy. Great, but it won't make the Science any more valid.

 Quote by sophiecentaur Yes, you are being perfectly polite, which is why we continue to converse with you. However, your initial question was not complete and was not asked in Scientific terms. That was the "behaviour" I was referring to.
Ok see your point. Sorry I asked it in layman’s terms, but people have got to start somewhere.

 Quote by sophiecentaur From your first post: "But what would be the impulse/force on/from the components/parts if the weight was lowered at the above vilocity, and for how long in 10ths or whatever in time would that higher force have to be untill the normal acceleration forces of the lift at rest."
Yes, that was quite a bad post.

 Quote by sophiecentaur Impulse and force are two different things. That's why two different words are used in Physics.
Yes I see that, here is my interpretation, hope you comment. I would say Impulse is a force acting on an object over a short period of time; like in the peak forces in my repetitions, as when I am lowering on the eccentric the weight, at say 2m/s for 20 inch, I then have to use my highest force I can in Milly seconds to slow, stop and restart the weight force the concentric. If I was using ??? 80 pounds, I “think” the impulse force ON my muscles for say a tenth of a second could be from 120 to 160 pounds ???

Then to me the rest of the concentric lift is the force used by the muscles to lift. Both are forces but one is the fast impact force, then there is the lower force to carry on the lift ???

This “very” high impact/impulse force, puts huge tensions on the muscles, and is a BIG part of this debate, as I say that the very high impulse with the high forces from the accelerations cannot be made up or balanced out by the lower forces of the slow repetitions. As not only do the muscles doing the fast have higher forces on the accelerations, they have the “EXTRA” forces from the say tenth of a second huge impact/impulse forces. I am sure D. has not added these in, actually I know he has not added these in, if you have time could you comment on that as well please, the huge impact/impulse force on the muscles from the fast that the slow does not have, as a small force applied for a long time can produce the same momentum change as a large force applied briefly, because it is the product of the force and the time for which it is applied that is important.

 Quote by sophiecentaur Likewise, for Force and Strength. So you ask about the relationship between one, non specific quantity and another, non-specific quantity. Is that scientific?
Ok sorry, see your point again.

But is not a force a push or pull, and that’s what the muscles strength does.

 Quote by sophiecentaur You claim that your machine tells you the force involved (in N) but then say that it reads electrical activity in μV. When you 'tense up' your arm, there is no net force at all (it stays still, in its original position) but there is loads of muscle activity,
Not fully with you on that one sorry, or maybe reading you wrong. As when I tense up my arm with the pads on the moving muscles, lets say the biceps and foararm in the curl or arm flextion, if I just tence those muscles the reading on the machine tells me, if I just hold the weight half way up the machine tells me, and when I miove the weight up and down the machine tells me, and tells me the high signals, with my muscles are producing high force, and the lower end of the signals where my muscles are producing the lower force. So this is a net force, when you tense and when you lift.

 Quote by sophiecentaur as your machine would show, but the antagonistic muscles are producing equal and opposite force.
No, only the antagonistic do “not” produce equal and opposite force in any barbell exercises, they produce very little force, maybe as little as 5 or 10% the agonist muscles do all the lifting and all the lowering. {actually the lowering or eccentric portion of the lift which the biceps and forearm does, {as well as the concentric} able a person to lower 40% more under control, say lower in 6 second, than the person can lift for their 1RM.

So no the antagonistic muscles are not producing equal and opposite force. As the biceps are the curling or flexing muscles, and the triceps are the extending muscles.

 Quote by sophiecentaur So there's no direct connection between muscle activity and force produced.
Yes there is, it’s a direct comparison. As if I lift 30% then 80% the readings like the peak force and average force will be far higher.

 Quote by sophiecentaur That is unless you have electrodes on every muscle group and the machine can do some complicated 'addition' of the effects of all the muscles.
You only need the pads on the lifting muscles, as these are the ones producing the force for both up and down.

Yes the machine does do very complicated equations instantly all the time.

 Quote by sophiecentaur You are still after some relationship between that muscle activity and the measurable work done on a weight when lifting it. But if it's possible to have loads of muscle activity and Zero work done, then there clearly is not one. Can you not accept that?
Yes I understand the concept of work, if I do not move the weight no work has been done, but there is still muscle activity, energy and force being used.
 Quote by sophiecentaur There is really no more to be said on the topic (except for another acre of figures about rep rates and pounds lifted).
I find it odd you say that, but after reading the about you might differ.

The Question.
You always fail faster about 50% faster in the faster repetitions, so if you fail faster, you “HAVE” used up your temporary force/strength, as you hit muscular failure faster thus you cannot lift the weight anymore. To me, if both Clones started the fast and slow lifting at the same time, as the slow Clone are still lifting the weights when the fast Clone has hit muscular failure and unable to lift the weight anymore, this “is/seems irrefutable, or categorically right to me, and I am not trying to sound smug or anything here, but if the slow Clone is still moving the weight, then the fast Clone “has” used up more overall or the total force/strength they had faster, if you see my point, please do you see what I am saying here ???

 Quote by sophiecentaur I can only suggest that you approach the manufacturers of your machine and ask them for their opinion.
These machines are/have been used in Hospitals and sports facilities for years, they are as efficient as your calculator, actually they are calculator/computers in another form. The machines are used as much as the everyday car; they are very well known and used.

http://medical-dictionary.thefreedic...ectromyography

 Quote by sophiecentaur They may well be more prepared to speak you language as it is in their interest to sell as many of those machines as they can. I think they will tell you that the machine gives a good indication of how much energy the muscles are transferring and / or the forces. I have no problem with that (the neurological application of the machine seem very worth while). They may even launch into some link between that and the mechanical work done. That will make you happy. Great, but it won't make the Science any more valid.
IF, you want to prove your physics equations right, you would need to “try” and answer the question above, and say why the below happens in the real World, as I am in contact; New Scientist Magazine, Physicstoday Magazine and Physics World Magazine. If you could be the first to solve the puzzle of how and why the equations and real World tests on this Phenomena is, maybe you could be in these Mags.

Thank you for your time and help.

Wayne

 So it's more like force is the AMOUNT of "pushing", regardless of the time or distance. Take for example when you press your hands together, there is a certain force, even though there is no distance, and the time has nothing to do with the force, except that it might decrease as you get tired, and will certainly vary somewhat over time. Consider if you took some dynamic(changing over time) situation and you had a spring in between something apply force and something being moved, you could take a snapshot at any time and determine the force being applied by measuring the spring(assuming you knew it's equilibrium length and spring constant), so time has nothing to do with it. An impulse has doesn't mean a sudden impact, and doesn't mean its "high"(especially as that is relative to what you are talking about[an elephant can probably handle much higher impulses than a mouse]). You can have an impulse of .0001N*S, taking place over an hour(theoretically), What makes it an impulse is that it is force taking place over time, not just the force we would see in a snapshot, but the measure of that "amount of pushing" for some "amount of time". The same way that acceleration would have a different meaning that acceleration for some amount of time(which is a change in velocity, [itex]/delta v[\itex]).

 Quote by waynexk8 The Question. You always fail faster about 50% faster in the faster repetitions, so if you fail faster, you “HAVE” used up your temporary force/strength, as you hit muscular failure faster thus you cannot lift the weight anymore. To me, if both Clones started the fast and slow lifting at the same time, as the slow Clone are still lifting the weights when the fast Clone has hit muscular failure and unable to lift the weight anymore, this “is/seems irrefutable, or categorically right to me, and I am not trying to sound smug or anything here, but if the slow Clone is still moving the weight, then the fast Clone “has” used up more overall or the total force/strength they had faster, if you see my point, please do you see what I am saying here ??? Wayne
Look Wayne...you're an adult person.You MUST be able to understand this.

You don't USE any force from any "temporary available force/strength".You use energy from the available energy to be able to apply force.Apples and oranges.If you're not able to understand those terms and use them correctly,no discussion can be done.

In fast lifting you apply the same average force for the same duration as in slow lifting or even as in just holding the weight hence the force-time integral("overall force") is identical in any case.That's the only known fact.

To answer again your question,you fail faster with fast lifting because the fluctuations of the SAME force require energy at a higher rate.NOT because you use more "overall force".
Physics don't have an answer why this happens.It happens because biology tells us that the fluctuations of force make the muscles more inefficient.

 Recognitions: Gold Member Science Advisor @Wayne Did you ever actually look up the definitions of the words we're all using? If you haven't yet looked up what Impulse means (in Physics) then you have absolutely no business using it. Likewise for all the other terms we are using. You want Physics so the least you can do is read something about it. I don't think you could distinguish a Physics answer from a BS answer, so far.
 Been ill in bed all day with Sinus problems, will get back to you all. Thank you for all the replies. Wayne

 Quote by sophiecentaur @Wayne Did you ever actually look up the definitions of the words we're all using? If you haven't yet looked up what Impulse means (in Physics) then you have absolutely no business using it. Likewise for all the other terms we are using. You want Physics so the least you can do is read something about it. I don't think you could distinguish a Physics answer from a BS answer, so far.
Did you miss my last post ??? I explained what Impulse is. Impulse is force multiplied by the amount of time it used over. Or a force that is applied to an object over a time frame, the overall or total force with time added in.

Ok I will ask you a question,
When I lift a weight from a still start, to a moving, there will be two different amounts of forces, as the impulse force is different. When two objects collide, there will be an impulse; the impulse causes a change of momentum/movement.

1,
I lift 100 pounds from a still start, upwards 20 inch in .5 of a second.

2,
The 100 pounds is being lowered under control from a still stat, lowered at 20 inch in .5 of a second. Immediately at the 20 inch, I lift the 100 pounds upwards 20 inch in .5 of a second.

My point, is that if you separately added the force of lifting a weight up and down 6 times, too adding the force from lifting it up and down constantly 6 times, it would different.

Wayne

 Quote by douglis Look Wayne...you're an adult person.You MUST be able to understand this. You don't USE any force from any "temporary available force/strength".
You “have” to use force to move the weight, so why do you say you, “don't” USE any force from any temporary available force/strength ??? You “have” to use force to move the weight

 Quote by douglis You use energy from the available energy to be able to apply force.
We ALL know you have to use energy to use the forces, we are NOT debating that you use more energy when you move something faster. We are debating the amount of force/strength use. “Why” bring up energy ???

 Quote by douglis Apples and oranges.If you're not able to understand those terms and use them correctly,no discussion can be done.
I understand that you use energy to create a force, but as I said, we are debating the amount of energy. It’s like how much force/strength must you use to lift 100 pounds one time 20 inch in 20 seconds, and how much force/strength must you use to lift 100 pounds ten times 20 inch in 60 seconds, or debate is similar to that. We are “NOT” on about the fuel/energy {calories} needed to fuel the force/strength. Or are you talking of something else, if so explain why and how you are talking about it.

 Quote by douglis In fast lifting you apply the same average force for the same duration as in slow lifting or even as in just holding the weight hence the force-time integral("overall force") is identical in any case.That's the only known fact.
1,
EMG states other.

2,
I fail faster in the faster reps, thus I “have” used up my tempery energy/force/strength.

3,
A weight of 100 pounds with an Acceleration of 20m/s, 100 x 200 = 20000N.
100 pounds with an Acceleration of 1m/s, 1 x 200 = 200N.
Ok we have to decelerate in the repping, however this deceleration will be very short, not the 40% as in the 1.5 time of the study.

 Quote by douglis To answer again your question,you fail faster with fast lifting because the fluctuations of the SAME force require energy at a higher rate.NOT because you use more "overall force".
Again, this is “NOT” an answer; the question is “WHY” the fluctuations of the force require energy at a higher rate. And it’s a direct contradiction on what you said, “IF” the fluctuations of the force require energy higher rate, “why” as you seem to think that the forces make up or balance out, if this was true the energies should/must also make up or balance out. As if my higher high or peck forces as you say take higher energies of fluctuations, then why does not my lowered force on the deceleration make up or balance out ??? As it should be high fluctuations high energies, low fluctuations low energies.

Fact is the higher energies are because the higher forces do and cannot be made up or balanced out by your lower forces, as the EMG states.

 Quote by douglis Physics don't have an answer why this happens.It happens because biology tells us that the fluctuations of force make the muscles more inefficient.