Where Does The Energy Come From ?

[deschoe]

 

 

Who do you think you are fooling?

 

A man who refuses to watch videos and a man who refuses to accept, neglecting friction, a horizontal movement means no physical work because the cubes have at the end the same velocity like at the start  ->

 

http://physics.stackexchange.com/questions/28155/does-moving-something-horizontally-in-gravity-do-no-work

 

 

[exchemist]

You can show a lot in a video, but you can also control what is seen and thus obscure reality.  I have watched enough Bugs Bunny to know that you can do things in animation that just won't work in reality.

Exactly. I have explained to deschoe earlier that this is one reason why I do not watch YouTube videos of unknown provenance. 

 

One can get lost in a swamp of asking for clarifications, which may or may not be forthcoming, of what exactly is being shown, what the exact demonstration setup is and so on. And all this without knowing whether the person one is talking to is acting in good faith or just trying to waste your time. Doctored videos are far from unknown. No thanks.

 

Whereas a written description with diagrams makes clear what is being attempted. One can easily read back and forth (which is not easy with a linear medium such as video) to check points and get a  clear picture - or at least identify for sure any aspect that is not clear.  

 

Last and not least, the writer is forced, by the very act of writing it down, to get his own ideas clear in his head and commit to a chain of argument.

[deschoe]

at first that nonses with the pressure jumps in the water and now his opinopn according physical work from exchem are one smoke granade after the other . ok look here :

 

Let's consider Scenario C above in more detail. Scenario C involves a situation similar to the waiter who carried a tray full of meals above his head by one arm straight across the room at constant speed. It was mentioned earlier that the waiter does not do work upon the tray as he carries it across the room. The force supplied by the waiter on the tray is an upward force and the displacement of the tray is a horizontal displacement. As such, the angle between the force and the displacement is 90 degrees. If the work done by the waiter on the tray were to be calculated, then the results would be 0. Regardless of the magnitude of the force and displacement, F*d*cosine 90 degrees is 0 (since the cosine of 90 degrees is 0). A vertical force can never cause a horizontal displacement; thus, a vertical force does not do work on a horizontally displaced object!!

It can be accurately noted that the waiter's hand did push forward on the tray for a brief period of time to accelerate it from rest to a final walking speed. But once up to speed, the tray will stay in its straight-line motion at a constant speed without a forward force. And if the only force exerted upon the tray during the constant speed stage of its motion is upward, then no work is done upon the tray. Again, a vertical force does not do work on a horizontally displaced object.

The equation for work lists three variables - each variable is associated with one of the three key words mentioned in the definition of work (force, displacement, and cause). The angle theta in the equation is associated with the amount of force that causes a displacement. As mentioned in a previous unit, when a force is exerted on an object at an angle to the horizontal, only a part of the force contributes to (or causes) a horizontal displacement. Let's consider the force of a chain pulling upwards and rightwards upon Fido in order to drag Fido to the right. It is only the horizontal component of the tension force in the chain that causes Fido to be displaced to the right. The horizontal component is found by multiplying the force F by the cosine of the angle between F and d. In this sense, the cosine theta in the work equation relates to the cause factor - it selects the portion of the force that actually causes a displacement.

-----------------------

and you see that horizontal movement means no work is done, so byebye CoE  :surprise:

 

aka http://public.wsu.edu/~jtd/Physics205/Chap6/CHAP6.html

Edited February 23, 2017 by deschoe

[Maine farmer]

Your cartoon shows a red arrow , but you do not show the magnitude of the force it represents.  You claim a temperature rise in the water without showing any sign of a thermometer.  Also, in the non cartoon part of the video, when the block is under water, it needs to be pushed several times, so the cartoon should show more than one red arrow there.  Without demonstrating what the force input is, or measuring the actual temperatures, or even offering any measurement of any force output, the video is cannot possibly show what you think it shows.  As for the cartoon part, if you could make it actually work, you wouldn't need the cartoon.  

Edited February 23, 2017 by Farming guy

[deschoe]

you want no cartoon you want it in real, and endless  please here is. same principle and same result

 

[Maine farmer]

Now we are back to the tweezer video.  Your block does not clear the top of the tube without being lifted with the tweezers.  For it to do what you think it does, the block would have to rise up all the way out of one tube, then fall without help into the other tube, and then  fall down below the bottom of the second tube and fall  up unaided back into the first tube.  This video very clearly shows a lot of effort and energy expended, and little if any produced.  Again, there are still no measuring devices to back up any claims of any output.

 

And so we have gone around in circles ourselves discussing this, and I suspect you will still reject these observations.  

[deschoe]

make the shown attemps yourself  or this discussion will be the first perpetual motion in history and think about why has exchamp äh exchem suddenly does shut up

Edited February 24, 2017 by deschoe

[Maine farmer]

Sorry, my available energy for this topic is used up.  I've done quite a lot of manual labor in my life, and I can recognize when something just takes too much work.

[deschoe]

sry so more than 10 minutes work are too much work for you, but you think you are an expert. thank you for this device

 

LOL

Edited February 24, 2017 by deschoe

[exchemist]

make the shown attemps yourself  or this discussion will be the first perpetual motion in history and think about why has exchamp äh exchem suddenly does shut up

"Prove me wrong!" is the cry of the crank down the ages.

 

In fact, it works the other way round in science. The burden of demonstrating a claim is valid rests on the one making the claim. And when the claim contradicts well established principles - as in this case - the burden on the claimant is especially heavy.  

 

As for why I have "shut up", I have explained that I will have no truck with shoddy videos as they lead to timewasting. 

 

But, to give you your due, your scenario is in fact quite interesting. So now I have a related scenario for you that demonstrates perpetual motion. It may help our collective understanding:

 

Imagine a vertical tube with one end immersed in a bowl of water and imagine half the air has been pumped out of the top of the tube with a vacuum pump and then sealed, so that a pressure of 0.5bar remains.  The water will rise 5m up the tube, right? You have in effect a water manometer. 

 

Now submerge one of your floats in the bowl and let it rise up inside the tube. It will float up to the top, right? 

 

Now let us further imagine one can introduce an airlock system at the top by which the float can be retrieved without losing the partial vacuum.  

 

You can extract the float and return it to the bottom, allowing it to do mechanical work as it does so.

 

And then you can repeat the cycle. Indefinitely! Free energy for all, yes? 

[deschoe]

watch the video. at 1.25 min, there you find the scenario you described. congratulation.!

 

and contradicts your upper statement not your buoyancy theory in case that the float is a little bit longer as the vertical tube ?

Edited February 24, 2017 by deschoe

[Maine farmer]

sry so more than 10 minutes work are too much work for you, but you think you are an expert. thank you for this device

 

LOL

It would take more than 10 minutes to setup and run a good experiment with precise measurements to collect good data

 

watch the video. at 1.25 min, there you find the scenario you described. congratulation.!

 

and contradicts your upper statement not your buoyancy theory in case that the float is a little bit longer as the vertical tube ?

Again you have the problem of the tweezers putting energy into the system.  What you show is interesting, and might make a good high school science fair project demonstrating surface tension and capillary action, but if you want it to be amazing, you have to get it to run without the tweezers or Bugs Bunny.

 

"None are so blind as those who refuse to see."  I don't know who said that, but it is so true.

[deschoe]

It would take more than 10 minutes to setup and run a good experiment with precise measurements to collect good data

 

Again you have the problem of the tweezers putting energy into the system.  What you show is interesting, and might make a good high school science fair project demonstrating surface tension and capillary action, but if you want it to be amazing, you have to get it to run without the tweezers or Bugs Bunny.

 

"None are so blind as those who refuse to see."  I don't know who said that, but it is so true.

thats absolutely right, but I only asked, where does the energy come from. and the sentence is from a binoculars producer

Edited February 24, 2017 by deschoe

[Maine farmer]

thats absolutely right, but I only asked, where does the energy come from. and the sentence is from a binoculars producer

Clearly the energy originates from the hands holding the tweezers!

[deschoe]

Clearly the energy originates from the hands holding the tweezers!

LOL

Edited February 24, 2017 by deschoe

[OceanBreeze]

 

 

Who do you think you are fooling?

 

A man who refuses to watch videos and a man who refuses to accept, neglecting friction, a horizontal movement means no physical work because the cubes have at the end the same velocity like at the start  ->

 

http://physics.stackexchange.com/questions/28155/does-moving-something-horizontally-in-gravity-do-no-work

 

 

 

 

 

Total bullshit.

 

The only way the cubes can have the same horizontal velocity at the end as they have at the beginning is to always be at the same horizontal velocity throughout the experiment. That is, obviously not the case, as they start out at rest, move horizontally at some velocity u, then finish at rest.

 

They undergo acceleration due to a force F being applied and the change in their kinetic energy is equal to the work done by the force F over the distance moved.

 

You can fool yourself, if you like, but you aren’t fooling anyone else with this bullshit.

 

I see your LOLs are getting bigger and bigger; a sign of desperation?

[exchemist]

Clearly the energy originates from the hands holding the tweezers!

Correct.

 

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

 

In my manometer example, the energy to lift the float up 5m comes from an equal mass of water descending the water column 5m. If the float is then lifted out of the water into the reduced pressure space above, its volume is added to the remaining air in the space and so the water column is permanently lowered by the rising of the float through it, just as if a bubble of air were allowed to rise up through it. So there is work done by gravity on the water, which balances the work done on the rising float. If you were somehow to magically extract the float through an airlock, you would have to do work against the pressure difference between the inside and the outside and this would correspond to pulling the mass of water that had descended back up the tube to its original height, as you withdrew the volume of the float from the air space. In other words, taking the float out would be like pumping air back out of the head space, so that the water rose once more to its original height.

 

The same applies in the capillary case. Here you lift the float out through the meniscus, moving from a slightly reduced pressure zone immediately below the meniscus back into the full atmospheric pressure environment above it, doing extra work which allows the displaced volume of water to return to where it was before the float was introduced. The tweezers do this, as you rightly say.  

 

This is actually a nice demonstration of the power of analysing physical scenarios from the perspective of energy. From an energy viewpoint it is obvious it can't work. To analyse all the steps by mechanics and hydrostatics involves quite a process.  

Edited February 25, 2017 by exchemist