Impulse/force in pounds for the time frame

In summary, the conversation discusses the question of what the maximum impulse force would be on the components/parts of a machine as it lowers and then immediately stops a weight of 100 pounds at 2m/s for 1000mm before lifting it back up at the same speed. The conversation also addresses the force needed to lift the weight from rest and how it would increase every 10th of a second during the lift. The conversation also touches on the issue of force units being measured in both US and SI units. It is suggested that the time interval during the accelerating phase must be about 1 second to stay within the limits of the machine, and it is noted that the conversation involves a man lifting the weight, which can complicate the
  • #36
waynexk8 said:
NO I do not, why would I ? I have been training for about 40 years, and it’s well known that you have to use antagonist’s muscles in order to slow, stop and very slightly reverse the weight

The case,for example,that you do a bicep curl and you decelerate with your triceps was not a part of the discussion.

I “proved” in my opinion I was right in my last post. Or could anyone here please try to explain that when you fail {and you do this is fact} in the faster repetitions,... Proof, evidence and facts, I have used my force/strength up first, thus if we both had 1000N of force/strength, I have used it up faster,
Wayne

I don't know what you think you prove with this example.
The fact that you fail faster with fast lifting just proves that you use energy faster(greater rate of energy expenditure) and not that you "use force/strength faster".
Greater rate of energy expenditure doesn't equate greater overall force.
Practically means that the fluctuations of force in fast lifting require more energy than the equal constant force of slow lifting.
 
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  • #37
Best I answer this one again.

douglis said:
The length of the acceleration phase is of little importance.

It makes all the importance. As the accelerations, are where the higher forces are, thus accelerations and higher accelerations thus higher forces. Yes you may say, but then there are the decelerations, however in my opinion, that medium force of the slow can “not” make up or balance out the high accelerates/forces of the fast, as the force impulse is higher.

douglis said:
As long as the terminal velocity is zero the acceleration is always balanced by the deceleration.Or...with your own words...the forces "make up".

You “need” to show “how” you “think” the force make up or balance out. As I keep repeating myself, but you do not cannot answer, so here again, “if” as you think the forces make up, why do I instantly use more energy when force goes up, and you “never” make the energy up, so “why” do you “think” you make the force up ?, then there is the more distance I move the weight, and I fail faster, you “never” can explain this.

douglis said:
However experimantally was found the acceleration phase lasts for about the half distance with the 80% of your maximum weight and much less with less weight when you try to lift as fast as possible.

NO, this was when bench pressing and the total repetition took 1.5 seconds, mine took .5 of a second.

douglis said:
In general,the faster the lifting the less the acceleration phase and the grerater the deceleration phase.

Why do you think this ? Please could we have explanations for the things you say, as this is a physicist site, and all needs proof and evidence.

douglis said:
BTW at the study you're referring the lifting lasts ~1sec which is perfectly normal with such weight.Check it again.

Sorry it was 1 seconds, “however” we are “not” on about any normal, we are on about one 3 second concentric to six .5 of a second concentric.

Wayne
 
  • #38
waynexk8 said:
Best I answer this one again.

Why do you think this ? Please could we have explanations for the things you say, as this is a physicist site, and all needs proof and evidence.

Well, at least you admit this is a Physics site. Having admitted as much, why do you refuse to talk Physics? The explanations you have been given make good sense in Physics and the only reason they don't make sense to you is that you refuse to talk the same language. This could be construed as simple arrogance by anyone less charitable than me!.
 
  • #39
waynexk8 said:
Best I answer this one again.
It makes all the importance. As the accelerations, are where the higher forces are, thus accelerations and higher accelerations thus higher forces. Yes you may say, but then there are the decelerations, however in my opinion, that medium force of the slow can “not” make up or balance out the high accelerates/forces of the fast, as the force impulse is higher.
You “need” to show “how” you “think” the force make up or balance out. As I keep repeating myself, but you do not cannot answer, so here again, “if” as you think the forces make up, why do I instantly use more energy when force goes up, and you “never” make the energy up, so “why” do you “think” you make the force up ?, then there is the more distance I move the weight, and I fail faster, you “never” can explain this.
NO, this was when bench pressing and the total repetition took 1.5 seconds, mine took .5 of a second.
Why do you think this ? Please could we have explanations for the things you say, as this is a physicist site, and all needs proof and evidence.
Sorry it was 1 seconds, “however” we are “not” on about any normal, we are on about one 3 second concentric to six .5 of a second concentric.

Wayne

The exact same questions from the last page again ignoring all the answers you've been given!If that's not obsession I don't know what else to call it.
I'm out of here...you got all the answers even graphically in a mail.Can't do anything more.
 
  • #40
"He only does it to annoy." Lewis Carol
 
  • #41
sophiecentaur said:
The equations are 'gong wrong' because you can't expect them to apply in a situation like this (as in all of your questions). You confuse the terms you use and seem to think that 'work done on' is necessarily related to 'energy transferred from muscles'.

Sophiecentaur, I am sincere and not a crank, I honestly want to learn, and have paid good money out for an EMG, so I do thank you for coming back into this debate and offering your knowledge.

Maybe I have in the pass I have confused the terms, but learning physics at my age is not that easy, if you or anyone started in my firm {wrought iron} it would not be easy for the first several years, but I am trying my best.

sophiecentaur said:
you use and seem to think that 'work done on' is necessarily related to 'energy transferred from muscles'.

When I say work, and as you know there a many words for work, I mean physical work, work is the product of a force times the distance. So if I move a weight from a to b as fast as I can, I have used as much force as I can, moving a weight so and so distance, and if I move it less distance in the same time frame I have used less force, that’s remember my opinion. However why I am here is that I do not know how to work out how much more force is used. Please see the video stating that more force was used, but this time the more force was used in less.



Fast
P = 695
F = 579
V = 192

Slow
P = 649
F = 546
V = 161

sophiecentaur said:
I really don't know why you want to include Physics in your training if you won't learn Physics to an appropriate level.

I am leaning a little. However the main/big point here, is that in the training World, this debate is huge; it’s been going on, on about 25 forums, by 10000 or more people for over ten years. However the majority, say 99% train fast, and results are spectacular to slow. Give the fat I trained 15 years trying slow, with not much results, that at the age of 45, added 30 pounds of muscle and 10 pounds of fat in just under 3 years doing faster repetitions.

And then again it’s just human to want to know debate and learn, like on this forums the debates have been so many, and some very long and complicated.

sophiecentaur said:
If you continue to talk in the wrong language, how can you expect to have a proper conversation . Quote "I have used up all my force" - this is a meaningless statement in terms of Physics. Your posts are full of such statements but you refuse to modify them or learn the appropriate way of putting things.

Ok I see you point there. But “how” else can I say this ? As if I use up all my force/strength, as I do in training, how else can I say this ?

sophiecentaur said:
If someone can only play the Piano with one finger then it's no surprise that a Piano Concerto gives them a problem.

Very true. But basically when training in this instance of both of the slow and fast person doing the two different velocities, we do use up our force/strength for a moment, or the moment of muscular failure, not sure how else to say it.

sophiecentaur said:
Like I have often said, you can't bend Physics to your will. You just have to follow where it takes you. You don't seem to want to, though.

I don’t want too, however all points the faster using more or more total force.

1,
My EMG reading states this.
2,
You use more energy when doing the fast, thus in my opinion as soon as you use more energy you use more force, what else can it be ?
3,
When the fast is on its deceleration, the slow cannot make up or balance out the higher force that the fast made when on its accelerations, as of more energy used, hitting muscular failure faster, moving the weight more distance, EMG readings, and all in the same time frame.
4,
As I have also said, If as you do, you fail faster doing the faster repetitions, you “must” have used up your momentary muscular force/strength faster than doing then slow.
5,
Then the video above.

I could say more, but “everything” points to you have to use more force. It’s like if you lift a heaver weight, you have to use more force, or if you lift the same weight faster you have to use more force, and in the end in my opinion more overall or total force.

Wayne
 
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  • #42
Wayne:

You are NOT sincere in wanting to learn about the Physics of this. You demonstrate this in nearly every one of your posts. Merely having forked out a load of your money on an "EMG" says nothing about your attitude to Physics or your sincerity.
Whilst you make statements like "When I say work, and as you know there a many words for work. . . ." then you are clearly never going to take in the Physics. There is just ONE definition of Work, in Physics but you seem to want to use the word to describe many things. You also use the word Force in any way you fancy but there is only one meaning for it (in Physics).

You haven't actually asked a question yet that 'parses' correctly in Physics nor have you accepted any of the totally straight answers you have been given. Are we all out of step but you?

It is a matter of GIGO, I'm afraid. You just succeed in pissing people off, here. Stick to your mates down at the Gym - they are more likely to speak your language. Alternatively, learn some actual Physics - and I don't mean Waynephysics.
 
  • #43
douglis said:
The case,for example,that you do a bicep curl and you decelerate with your triceps was not a part of the discussion.

I never said it was part of the debate, you brought it up.

douglis said:
I don't know what you think you prove with this example.
The fact that you fail faster with fast lifting just proves that you use energy faster(greater rate of energy expenditure) and not that you "use force/strength faster".

Just look at what you said and the contradiction. When you can “not” lift anymore, it means you do “not” have the force/strength to lift the weight true or false ? We all know that’s true, if not state why ? So why try and say you use energy faster, we all know you do, “too which is contradiction of sorts again” as “why” do you use more energy faster ? Exactly the same time you move faster, it’s because you “are” using up force/strength faster.

Ok please tell me why I fail faster and cannot pick up the weight ? I will say its because of several reasons, but it’s basically you force/strength supply has ran out temporary ? Yes or no ? And also your energy supply has ran out temporary ? Yes or no. You can “not” just blame it on energy, you “have” to add in the force, as the force is what the energy is powering.

If you say yes, then its force and energy has ran out together, and that’s because you using up your force sulphide with energy faster, if not why ? You can’t have one without the other.
Greater rate of energy expenditure doesn't equate greater overall force.

douglis said:
Practically means that the fluctuations of force in fast lifting require more energy than the equal constant force of slow lifting.

Yes this is what I am saying also, the higher force “must” use more of the force that the muscles have. The fluctuations of force in fast lifting must also require “more” force out of the available force the muscles than the constant force of slow lifting, how can it be any other way ?

Now please answer this.
When you fail {and you do this is fact} in the faster repetitions, too which that means you have no force/strength left, but the person doing the slower repetitions does have force/strength left, how can I have not used all my force/strength up faster when I have used my force/strength up 50% faster ? Proof, evidence and facts, I have used my force/strength up first, thus if we both had 1000N of force/strength, I have used it up faster, to say other would be a full English and physics contradiction, it would be like say the Man who ran the 100m the slowest was the fastest.

Wayne
 
  • #44
Wayne. That is just a rant. what do you want (one sentence please) out of all this?
 
  • #45
waynexk8 said:
The fluctuations of force in fast lifting must also require “more” force out of the available force the muscles than the constant force of slow lifting, how can it be any other way ?
The fluctuations of force in fast lifting must also require “more” energy out of the available energy than the constant force of slow lifting


Now please answer this.
When you fail {and you do this is fact} in the faster repetitions, too which that means you have no force/strength left,
Wayne

When you fail in the faster repetitions means you have no energy left.

Wayne...are you able to understand the difference between force and energy?
 
  • #46
sophiecentaur said:
Wayne:

You are NOT sincere in wanting to learn about the Physics of this. You demonstrate this in nearly every one of your posts. Merely having forked out a load of your money on an "EMG" says nothing about your attitude to Physics or your sincerity.

I am or will try to learn as much as I can, but I have a firm, family and many other things in life, I just do not have the time to do a full physics course, will will try to learn what I need for this debate.

Please say the odd thing I say wrong, then I can either explain or put it right.

sophiecentaur said:
Whilst you make statements like "When I say work, and as you know there a many words for work. . . ." then you are clearly never going to take in the Physics. There is just ONE definition of Work, in Physics but you seem to want to use the word to describe many things.

In this instance it must mean physical work, as that’s what we are doing, if not what do I call it ? But is not work the product of a force times the distance add in time ? If so then it’s the same.

sophiecentaur said:
You also use the word Force in any way you fancy but there is only one meaning for it (in Physics).

Force is basically a push or pull, it makes an object move, that’s roughly the same as strength. Not sure what you say I got wrong there ? Please say.

sophiecentaur said:
You haven't actually asked a question yet that 'parses' correctly in Physics

I think I have, if not please say how I should ask this question from this example.

I use muscle strength to make force, so I use force to move a weight. I only have so much temporary force in my muscles, like everything else. So if I lift 80% of my 1RM, at a velocity of .5/.5 and 3/3 you will fail roughly 50% faster moving on the faster, this means I have gone to momentary muscular failure, and used up my temporary force faster than the slow. This must in my opinion mean I have used more total or overall force faster. The debate was, which uses the most total or overall force on the temporary force the muscles have, thus put more tension on the muscles in the same time frame. 1 repetition at 3/3 = 6 seconds, or 6 repetitions at .5/.5 = 6 seconds, or/and 4 repetitions at 3/3 = 24 seconds or 24 repetitions at .5/.5 = 24 seconds. Not sure how else to say it.

however all points the faster using more or more total force.

1,
My EMG reading states this.
2,
You use more energy when doing the fast, thus in my opinion as soon as you use more energy you use more force, what else can it be ?
3,
When the fast is on its deceleration, the slow cannot make up or balance out the higher force that the fast made when on its accelerations, as of more energy used, hitting muscular failure faster, moving the weight more distance, EMG readings, and all in the same time frame.
4,
As I have also said, If as you do, you fail faster doing the faster repetitions, you “must” have used up your momentary muscular force/strength faster than doing then slow.
5,


Fast
P = 695
F = 579
V = 192

Slow
P = 649
F = 546
V = 161


I could say more, but “everything” points to you have to use more force. It’s like if you lift a heaver weight, you have to use more force, or if you lift the same weight faster you have to use more force, and in the end in my opinion more overall or total force.

sophiecentaur said:
nor have you accepted any of the totally straight answers you have been given. Are we all out of step but you?

See 1 to 5, all point to more force/strength being used by the faster repetitions.

sophiecentaur said:
It is a matter of GIGO, I'm afraid. You just succeed in pissing people off, here.

Sorry, I did/do not mean that, I am only trying to get an answer, but when I put practical answer, or what actually happens, some people think/seem they can ignore this and in turn do not, or cannot answer, and I don’t understand this. Let me say it short again, if I hit muscular failure faster, have not I used up my temporary force/strength, than the person who is still doing the repetitions but slower ? If not what answer would you give ?

sophiecentaur said:
Stick to your mates down at the Gym - they are more likely to speak your language. Alternatively, learn some actual Physics - and I don't mean Waynephysics.

I have been polite all along, I came here to learn, and will try to learn more.

sophiecentaur said:
Alternatively, learn some actual Physics - and I don't mean Waynephysics.

Just take 1, if an EMG machine says I have more muscle activity, I would have thought people would want to understand this, or find out more. I don’t call an EMG Waynephysics, its World physics.

Please sophiecentaur, I do thank you for your time and help, but I do not want to turn this into anything else except a nice friendly debate, and would rather just talk physics and practical World equations/tests.

Wayne
 
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  • #47
waynexk8 said:
Just take 1, if an EMG machine says I have more muscle activity, I would have thought people would want to understand this, or find out more. I don’t call an EMG Waynephysics, its World physics.

Please sophiecentaur, I do thank you for your time and help, but I do not want to turn this into anything else except a nice friendly debate, and would rather just talk physics and practical World equations/tests.

Wayne

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?

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.
 
  • #48
douglis said:
The fluctuations of force in fast lifting must also require “more” energy out of the available energy than the constant force of slow lifting

You contradict and repeat.

The fluctuations of force in fast lifting, as in the higher fluctuations of force must also require “more” energy, as they are using “more” force and “more” of the temporarily force/strength that is available, how else can you use more energy if it’s not used up by more of the fluctuations of force in fast lifting, as in the higher fluctuations of force. And as both lifting slow and fast have the same temporary force/strength, why is it not used up in slow so fast ? As it must be using less of its available temporary force/strength.

We all know this, and is it not because when you use a higher force out of the temporary available force/strength you “have” to be using more of the temporary available force/strength ? How else can you use more energy ? I repeat, Its because you “have” to be using more of the temporary available force/strength, “if” you did not use more of the temporary available force/strength, like you in the slow, you will and do have more force/strength left, as you do.

Please could you or anyone else just try and answer the above ?

douglis said:
When you fail in the faster repetitions means you have no energy left.

You contradict and repeat again.

Force/strength is what the energy is powering, so when the temporary force/strength is used up, the energy is used up, or when the energy is used up, the temporary force/strength is used up, and you can’t have one used up without the other in this instance. I repeat as above, the higher.

douglis said:
Wayne...are you able to understand the difference between force and energy?

Odd question to ask, the energy, is the energy that in this case is the energy for the muscular force/strength, to which the muscles force/strength moves the weight. And you as you know only have so much energy and force for a certain time frame of lifting. You are trying to say the energy is used up because of nothing ? But it’s the force/work that the muscles are doing that uses up this energy, and if you use “more” force/strength faster, the energy gets used up faster.

Wayne
 
  • #49
waynexk8 said:
you “have” to be using more of the temporary available force/strength
Wayne

That's NONSENSE.You don't use more "force" from the "temporary available force".You use more energy from the available energy to be able to apply force.
That doesn't mean you use more overall force...it means you use energy at a higher rate.Apples and oranges.

Look...that's enough.You created your own physics and terms to feed your obsession and you want us somehow to understand your nonsense and agree with you.That's too crazy even for you.
 
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  • #50
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.
 
  • #51
douglas wrote;That's Waynesphysics.Greater energy expenditure doesn't equate greater force.

Yes it does, we covered this in another debatehere on this forum. I thought everyone knows and agrees on this, you only have to go to any nutritional site of book to find this out. You “can not” move faster without “more” force, you “can not” use more force without using more energy, to say other trying to alter physics. WHY are we going here again.

Now for another contradiction.

douglas wrote;You spend more energy in fast lifting because it takes more energy to generate force than to maintain it.

You just said, I quote; Greater energy expenditure doesn't equate greater force you then say and contradict yourself, I quote; You spend more energy in fast lifting because it takes more energy to generate force

douglas wrote;You spend more energy in fast lifting because it takes more energy to generate force than to maintain it.

Yes yes yes, this is what I am and have been saying all along, bingo, yes it “does” take more energy to produce and generate more {more as in the longer you try and use force} and higher force than to maintain it, as in holding the weight half way up, or moving the weight up slow like in the slow repititions.

douglas wrote;It's a purely biological matter.

On a physics site, this is not an answer; it seems a way of getting round, you don’t seem to know. Or do you mean to move faster takes more force and higher force, and thus energy. In the fast you use more power, 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.

You seem to be thinking energy is the force, it’s not, energy is the energy powering the force/strength of the muscles, and basically the muscles fuel is adenosine triphosphate or simply ATP, Creatine, phosphagen, glycolysis, and oxidative. I repeat, if you only have a certain amount of force/strength, when say lifting 80% {and we all do only have a limited force/strength to use} the faster, or the more of this limited force/strength you use, the faster the total or overall force/strength is used. So use low force/strength slower like you, and it “will” last longer, as it does, as you hit muscular failure about 50% slower doing the repetitions slower.

Wayne
 
  • #52
sophiecentaur said:
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
 
  • #53
waynexk8 said:
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.
 
  • #54
@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 textbook 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.
 
  • #55
sophiecentaur said:
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.
 
  • #56
sophiecentaur said:
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.

http://www.google.co.uk/url?sa=t&rc...ErnCDx9vBBJgACT0w&sig2=llkClBp3LlPMSx1wQ9VEsg

http://www.google.co.uk/url?sa=t&rc...ErnCDx9vBBJgACT0w&sig2=llkClBp3LlPMSx1wQ9VEsg

Here is the one I bought.

http://www.tensmachines.co.uk/NeuroTrac-ETS-EMG-For-the-Professional_p_133.html [Broken]

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 ?



sophiecentaur said:
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 don't understand what I am saying.


Thank you again for your time.


Wayne
 
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  • #57
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.
 
  • #58
sophiecentaur said:
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.

sophiecentaur said:
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
 
  • #59
sophiecentaur said:
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 ?

sophiecentaur said:
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 traveling 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/ency/article/003929.htm

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

http://www.youtube.com/watch?v=B8gtp...ofilepage#t=3s


http://www.youtube.com/watch?v=pd0ZA...ofilepage#t=1s

sophiecentaur said:
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.

sophiecentaur said:
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.

sophiecentaur said:
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/Biomechanical%20Evaluation%20of%20Movement%20in%20Sport%20and%20Exercise.pdf [Broken]



sophiecentaur said:
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 ?

sophiecentaur said:
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 learned 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
 
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  • #60
waynexk8 said:
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?
 
  • #61
waynexk8 said:
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.

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 until 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.
 
  • #62
sophiecentaur said:
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.

sophiecentaur said:
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 until the normal acceleration forces of the lift at rest."

Yes, that was quite a bad post.

sophiecentaur said:
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.

sophiecentaur said:
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.

sophiecentaur said:
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, let's 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.

sophiecentaur said:
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.

sophiecentaur said:
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.

sophiecentaur said:
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.

sophiecentaur said:
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.
sophiecentaur said:
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.

What about this question then ? I am sure you can talk or understand scenarios outside of physics ? Like other branches of physics, kinology, biomechanics. Or, just thought of this, let’s say your back at university, and you have to do a practical test and scenario for your PhD, and the Lecturer asks you the below, and you have to answer. Or could you just have a go for me, or suggest another way I can ask it, but as a physics adviser, I thought you would like to try and work out how the equations do not add up in the real World tests/experiments as in below ? Please ? As I don’t see how you can step outside the box, as I thought all physics should be tested in the real World after they have been calculated on paper.

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 ?

sophiecentaur said:
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.thefreedictionary.com/electromyography

sophiecentaur said:
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
 
  • #63
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]).
 
  • #64
waynexk8 said:
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.
 
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  • #65
@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.
 
  • #66
Been ill in bed all day with Sinus problems, will get back to you all.

Thank you for all the replies.

Wayne
 
  • #67
sophiecentaur said:
@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
 
  • #68
douglis said:
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

douglis said:
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 ?

douglis said:
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.


douglis said:
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.

douglis said:
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.

douglis said:
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.

Physics dose have an answer.

Wayne
 
  • #69
waynexk8 said:
Physics dose have an answer.

Wayne

If you're the Expert now, on what Physics can and can't do, then I suggest you answer the question yourself. I have just read your comments on Douglis's post and it is clear that you don't even read his sentences to the end. I have to conclude that you find us all to be totally incompetent in the field of Physics so I suggest you go and find a Forum in which the contributors know enough of the right sort of Physics to satisfy you.
Does it, for one minute, strike you that your whole idea could just be flawed? Your resolute use of the nonsense expression "force / strength" and others, demonstrates that you just don't really want to get to grips with the real stuff. Just why do you keep posting here?
 
  • #70
waynexk8 said:
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

For God's sake...read my whole sentence and try to make your brain work.
You DON'T use force.You use energy to apply force.I "bring up" the energy thing because higher energy usage(as in fast lifting) does NOT equate greater force application.
Apples and oranges.Only in Wayne's world those two mean the same thing.

1,
EMG states other.

Your EMG states greater quadratic mean(RMS) as expected since in fast lifting the force has greater peaks.

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

Here it is again!Are you able to understand the difference of these three?

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.Wayne

The acceleration is always exactly balanced by the deceleration regardless the length of each phase.That's why the average force is always equal with the weight.

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

NONSENSE.
The force-energy relation is NOT linear.The force "balances out" while the energy NOT
.
 
Last edited:
<h2>1. What is impulse?</h2><p>Impulse is a measure of the change in momentum of an object. It is equal to the force applied to an object multiplied by the time for which the force is applied.</p><h2>2. How is impulse calculated?</h2><p>Impulse is calculated by multiplying the force applied to an object by the time for which the force is applied. The unit of impulse is Newton-seconds (N·s) in the metric system, or pound-seconds (lb·s) in the imperial system.</p><h2>3. What is the relationship between impulse and force?</h2><p>Impulse and force are directly proportional to each other. This means that the greater the force applied to an object, the greater the impulse will be. Similarly, the longer the force is applied, the greater the impulse will be.</p><h2>4. How is impulse related to change in momentum?</h2><p>Impulse is equal to the change in momentum of an object. This means that the impulse applied to an object will result in a change in its momentum. The direction of the change in momentum will depend on the direction of the force applied.</p><h2>5. How is impulse measured in pounds for a specific time frame?</h2><p>In the imperial system, impulse is measured in pound-seconds (lb·s). This means that the force applied must be measured in pounds (lb) and the time for which the force is applied must be measured in seconds (s).</p>

1. What is impulse?

Impulse is a measure of the change in momentum of an object. It is equal to the force applied to an object multiplied by the time for which the force is applied.

2. How is impulse calculated?

Impulse is calculated by multiplying the force applied to an object by the time for which the force is applied. The unit of impulse is Newton-seconds (N·s) in the metric system, or pound-seconds (lb·s) in the imperial system.

3. What is the relationship between impulse and force?

Impulse and force are directly proportional to each other. This means that the greater the force applied to an object, the greater the impulse will be. Similarly, the longer the force is applied, the greater the impulse will be.

4. How is impulse related to change in momentum?

Impulse is equal to the change in momentum of an object. This means that the impulse applied to an object will result in a change in its momentum. The direction of the change in momentum will depend on the direction of the force applied.

5. How is impulse measured in pounds for a specific time frame?

In the imperial system, impulse is measured in pound-seconds (lb·s). This means that the force applied must be measured in pounds (lb) and the time for which the force is applied must be measured in seconds (s).

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