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Where Does The Energy Come From ?


deschoe

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ok. then please calculate, how many work you have done, in W,    .

 

A book lays on a table. next you move this book 10 cm from left to right, and then the book lays again in idle state. 

 

how many physical work you have done, in W please and you can neglect friction

 

->  https://en.wikipedia.org/wiki/Work_(physics)

 

 

OK. This is very simple, deshoe.

 

Let the book have a mass of 1 kg. You want to accelerate it from rest to a constant velocity of 1 m/s in as short a time as possible. Let the acceleration occur in 1 millisecond.

 

Acceleration = dv/dt = 1 m/s /.001 sec = 1000 m/s^2

 

F=ma, Force = 1 kg x 1000 m/s^2 = 1000 Newtons

 

S = 1/2 at^2 = 0.0005m, this is the distance travelled during the period of acceleration

 

Work = Force x Distance  = 1000N x 0.0005 m = 0.5 Watts

 

As a crosscheck, as I said earlier the work is equal to the change in kinetic energy

The book starts with zero KE and after being accelerated to 1 m/s the KE = 1/2 M v^2 = 0.5 J/s

And that agrees with the work-energy theorem 0.5 Joules/sec = 0.5 Watts

 

The same thing happens at the receiving end, when the cubes must be slowed back down to rest. The total energy expended is 1 Watt.

 

Now, you can do the same thing with your little cubes. You already have the mass, you just need to

Delineate the constant velocity they are to be transferred at and how fast you want them accelerated.

 

If you give me those numbers, I will calculate the amount of work and energy needed, or now that you have an example, you should be able to do it yourself.

 

There is no escaping the fact that energy is needed in the horizontal transfer of the cubes, and in your demonstration, that energy is being provided by the person operating the tweezers, as has already been pointed out to you.

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In fact, the process is quite subtle, though and I commend deschoe for providing us with a brain-teaser.

 

 

 

 

You are giving him way too much credit! There is nothing the least bit subtle about this and it certainly does not qualify as a brain teaser. He is ignoring the energy needed to accelerate the cubes from rest to some constant velocity. All crackpots try to ignore some inconvenient fact in arriving at their version of perpetual motion.

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You are giving him way too much credit! There is nothing the least bit subtle about this and it certainly does not qualify as a brain teaser. He is ignoring the energy needed to accelerate the cubes from rest to some constant velocity. All crackpots try to ignore some inconvenient fact in arriving at their version of perpetual motion.

We're talking at cross-purposes, I think.

 

You can consider the horizontal motion in this case to take place arbitrarily slowly. The slower it is, the less kinetic energy has to be input. In the limiting case, when it takes place at an infinitesimal rate, then no work is done in a purely lateral frictionless motion. (cf. Carnot cycle, in which expansion is deemed to take place infinitesimally slowly - or "quasi-statically"- , in order to keep the process reversible.) One is entitled to make similar assumptions here, I think, if one wants to get at the fundamental reason why no "free energy" is produced. (apart from the obvious violation of the 1st Law, which our poster wants to challenge, apparently.)

 

My explanation is concerned with the inevitable input of work required to repeat the cycle, in however efficient and loss-less a manner it is done.   

Edited by exchemist
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We're talking at cross-purposes, I think.

 

You can consider the horizontal motion in this case to take place arbitrarily slowly. The slower it is, the less kinetic energy has to be input. In the limiting case, when it takes place at an infinitesimal rate, then no work is done in a purely lateral frictionless motion. (cf. Carnot cycle, in which expansion is deemed to take place infinitesimally slowly - or "quasi-statically"- , in order to keep the process reversible.) One is entitled to make similar assumptions here, I think, if one wants to get at the fundamental reason why no "free energy" is produced. (apart from the obvious violation of the 1st Law, which our poster wants to challenge, apparently.)

 

My explanation is concerned with the inevitable input of work required to repeat the cycle, in however efficient and loss-less a manner it is done.   

 

I don’t see where we have any disagreement.

 

Quasistatic approximation:

"In simple cases, the quasistatic approximation is allowed when the typical spatial scale divided by the typical temporal scale is much smaller than the characteristic velocity with which information is propagated"

 

I am not at all sure that applies here. I suspect you may be over thinking this a bit.

 

 He obviously thinks a book can be moved from rest a distance (10cm) at constant velocity and returned to rest without doing any work, and I have clearly showed that is wrong. He has never claimed his cubes move quasistatically.

 

I think we can agree that by either your explanation or mine, his claim is bunk, and mine is simpler! :nahnahbooboo:

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I don’t see where we have any disagreement.

 

Quasistatic approximation:

"In simple cases, the quasistatic approximation is allowed when the typical spatial scale divided by the typical temporal scale is much smaller than the characteristic velocity with which information is propagated"

 

I am not at all sure that applies here. I suspect you may be over thinking this a bit.

 

 He obviously thinks a book can be moved from rest a distance (10cm) at constant velocity and returned to rest without doing any work, and I have clearly showed that is wrong. He has never claimed his cubes move quasistatically.

 

I think we can agree that by either your explanation or mine, his claim is bunk, and mine is simpler! :nahnahbooboo:

We're not disagreeing, and we all know his claim is bunk because of the 1st Law, but we are talking about different things. 

 

My point is that even if you leave aside the practical issue of moving things sideways, and consider only the work done by and against gravity, by and against capillary attraction and by and against the atmosphere - which he can do if he wants to make this a theoretical discussion about ideal systems, rather than a practical device -  then he is overlooking the work done against the atmosphere to lift something out through the meniscus.

 

You have to lift the thing out if you wish to return to the status quo and thus have a continuous cycle. And however you do that, quasistatically or not, you have to put work in, not just against gravity but against the things I have been talking about.  

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Let the book have a mass of 1 kg. You want to accelerate it from rest to a constant velocity of 1 m/s in as short a time as possible. Let the acceleration occur in 1 millisecond.

 

Acceleration = dv/dt = 1 m/s /.001 sec = 1000 m/s^2

 

F=ma, Force = 1 kg x 1000 m/s^2 = 1000 Newtons

 

S = 1/2 at^2 = 0.0005m, this is the distance travelled during the period of acceleration

 

Work = Force x Distance  = 1000N x 0.0005 m = 0.5 Watts

 

As a crosscheck, as I said earlier the work is equal to the change in kinetic energy

The book starts with zero KE and after being accelerated to 1 m/s the KE = 1/2 M v^2 = 0.5 J/s

And that agrees with the work-energy theorem 0.5 Joules/sec = 0.5 Watts

 

The same thing happens at the receiving end, when the cubes must be slowed back down to rest. The total energy expended is 1 Watt.

 

 

congatulation, you disprooved the CoE. why ?

 

because the book has after moving the same status of energy, namely its potential energy, because the book has the same level before and after, when the book has no kinetic but only potential energy.   so, if you had an input of 1 W, this done work doesnt appear anyway, so done work, thats appears nowhere means bye bye CoE

 

LOL

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congatulation, you disprooved the CoE. why ?

 

because the book has after moving the same status of energy, namely its potential energy, because the book has the same level before and after, when the book has no kinetic but only potential energy.   so, if you had an input of 1 W, this done work doesnt appear anyway, so done work, thats appears nowhere means bye bye CoE

 

LOL

Don't be silly. If you give the book some kinetic energy by accelerating it from rest, using for example the chemical energy of your muscles, you also have to decelerate it to rest again, e.g. by allowing friction to stop it, at which point the kinetic energy gets converted to heat. My son could get this sort of thing right at the age of 10.

 

If you keep maintaining that simple scenarios like this one also disobey the 1st Law, then we will be forced to conclude you are a disingenuous troll, rather than just a free energy crank.  I'd far rather think of you as a crank, because one can at least have a discussion with someone who is acting in good faith.

Edited by exchemist
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congatulation, you disprooved the CoE. why ?

 

because the book has after moving the same status of energy, namely its potential energy, because the book has the same level before and after, when the book has no kinetic but only potential energy.   so, if you had an input of 1 W, this done work doesnt appear anyway, so done work, thats appears nowhere means bye bye CoE

 

LOL

 

Oh Jeez. It always comes down to the same thing with you perpetual motion people, doesn’t it? Whenever a force is applied and a displacement results, work is being done. When you move the book from rest you are doing work on the book. Now the book has kinetic energy. To stop the book it has to lose all of that KE. And if there are no losses, where does it go? It goes to the Ultimate Kinetic Energy Recovery System (KERS) otherwise known as The Earth! And that is only considering the external work. As exchemist has pointed out, there is also the internal work such as done by the muscles burning glucose from what you have eaten for breakfast.

 

But, you win, Deshoe! (does the D stand for Delbert, I wonder) I think I have had enough of this. I leave you to continue your argument for the World’s First Perpetual Motion Machine by convincing Exchemist of this wonders of this most amazing thing you have done! :bow: :bow:  :bow:  

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i am still waiting for the calculation, in W please, how many physical work has to be done, to move the book on the table in horizontal direction. at least I red inhere 1 W, but I am sure I am the one who needs help, not the rest inhere

 

and as anybody can read inhere, the clever guys, who think they can give help to  less smarter ones obviously like me, are surely able to explain the readers of this thread, why they did have to invest 1 W to move the book on the table, and especially why they did not hurt the CoE themselves by the lost of 1 W in the energy amount of the whole universe since the big bang

 

LOL

Edited by deschoe
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i am still waiting for the calculation, in W please, how many physical work has to be done, to move the book on the table in horizontal direction. at least I red inhere 1 W, but I am sure I am the one who needs help, not the rest inhere

 

and as anybody can read inhere, the clever guys, who think they can give help to  less smarter ones obviously like me, are surely able to explain the readers of this thread, why they did have to invest 1 W to move the book on the table, and especially why they did not hurt the CoE themselves by the lost of 1 W in the energy amount of the whole universe since the big bang

 

LOL

and i am still waiting where is the lost 1 W ?  @breeze, guy and ex

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It might amuse readers to know this guy has been hawking the same crap all over the internet since mid-December last year: I had a quick look in an idle moment:

 

http://www.perplexingproblems.com/forums/topic/why-isnt-it-a-pm/

 

http://www.unexplained-mysteries.com/forum/topic/301513-perpetual-motion/

 

https://able2know.org/topic/357697-1

 

https://freeenergyforum.com/discussion/463/first-real-existing-perpetual-motion-/

 

 

We have the honour (or shame?) of having entertained/indulged him far longer than any of these other forums did.

 

But, at last, I think, it's enough, now. 

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