Atwoods Analysis

[Fletcher]

There you go - seems your atwoods can be adapted for the purpose quite easily to test the second part of the theory of exchange of momentum for velocity of a lesser mass.

[pequaide]

Yes it would, that is why I am interested in the pillow block. Just the shaft with the gears attached would be quite impressive. Find the mass of the shaft and gear combination and multiply it by about .6 for the radius of gyration and then divide that by ten. Then find a sphere that has about this (mass * .6 / 10) mass and some fluorocarbon fishing line and you are in business. One wrap around the gear will certainly stop the shaft. You might have trouble with the string slipping off the side of the gear with such a narrow disk. You might have enough velocity to chip the teeth of the gear; but I don’t know why the sphere would come back around and hit the gear. The sphere usually hits something else first. Provide a cushioned area for the sphere to dissipate its energy, other than your temple.

[Fletcher]

I assume you mean a vertical orientation pequiade ? i.e. the flywheel has a horizontal axle.

Here's something to think about - first rigid arms that deploy are more controllable & manageable IMO, but you're the man who did the experiments, hence broli's device although he preferred the horizontal alignment where Cf's/Cp's did the job without gravity confusing the issue.

As the flywheel mass increases & the atwoods differential is least the rpm of the flywheel may be quite slow - will that be enough to deploy the tethered weights fully i.e. enough input energy given to the device to set properly ? - if the atwoods differential is large & the flywheel less massive then the rpm will be greatest but there will be less momentum to give to velocity of a tethered weight ?! - the optimum must be able to be calculated or at least a predictive spread sheet built over a range of variables ?

[pequaide]

Yes: you need higher speeds with the vertical wheel because gravity does interact. Release the sphere at different angles; and somewhere in there you get the motion you are looking for. Around 6 o’clock seems to work well.

[broli]

Peq you should visit Wubbly if he doesn't live too far, that way you setup the experiment and he records and presents the data. Wubbly has presented his data in a way I have been trying to convince you peq. Too bad his presentation skills have been used on something not very related to momentum transfer.

[Wubbly]

The more I think about this experiment, the more things I see. Another interesting thing to note is that although we used various mass, acceleration combinations, and various time factors were involved, the kinetic energy equation predicted the same outcome for each, and the spring length was roughly the same for each. It would probably lead someone to conclude that the quantity "1/2 mass x velocity squared" is not a mathematical abstraction, but a reality.

Viewing the experimental results, you can see that the theoretical momentum keeps increasing while the kinetic energy does not. Extrapolating the results to extremes, one can see that as the acceleration gets closer and closer to zero, the momentum still keeps increasing. It doesn't seem logical to assume you can get more and more out of something that is accelerating less and less. As the acceleration approaches zero, you get virtually infinite momentum. If momentum measured the capacity to do work, you could get almost infinite work out of virtually no acceleration. No matter how deep a thinker you might be, it would not be logical to conclude the increased momentum from this experiment could lead to increased work or energy available.

[Wubbly]

I was wrong when I said there is no law of conservation of kinetic energy. If you watch MIT professor Walter Lewin's lecture 29, he says that with an inelastic collision, momentum is conserved and kinetic energy is not.
With an elastic collision, momentum is conserved and kinetic energy is also conserved. So there is a condition where kinetic energy is conserved.

Here is MIT professor Walter Lewin's lecture 29.
http://www.youtube.com/watch?v=H9otEyp1 ... B2FF119649

[Wubbly]

Looking at the "momentum_KE_combinations" spreadsheet on page 5 of this thread showing various mass, velocity combinations and their momentum and kinetic energy values, it was pointed out previously that if you could give all of the momentum of a large mass to a small mass, there would be energy increase. But on the flip side of the coin, if you look at the bottom part of the spreadsheet, for a given amount of kinetic energy, a large mass needs a higher momentum value to equal the kinetic energy of a smaller mass. This experiment seems to be supporting this latter condition. So in this experiment, one might say that the best case condition is the lighter mass falling quicker, since you get the same energy for the least amount of momentum.

[greendoor]

The more I think about this experiment, the more things I see. Another interesting thing to note is that although we used various mass, acceleration combinations, and various time factors were involved, the kinetic energy equation predicted the same outcome for each, and the spring length was roughly the same for each. It would probably lead someone to conclude that the quantity "1/2 mass x velocity squared" is not a mathematical abstraction, but a reality.

Viewing the experimental results, you can see that the theoretical momentum keeps increasing while the kinetic energy does not. Extrapolating the results to extremes, one can see that as the acceleration gets closer and closer to zero, the momentum still keeps increasing. It doesn't seem logical to assume you can get more and more out of something that is accelerating less and less. As the acceleration approaches zero, you get virtually infinite momentum. If momentum measured the capacity to do work, you could get almost infinite work out of virtually no acceleration. No matter how deep a thinker you might be, it would not be logical to conclude the increased momentum from this experiment could lead to increased work or energy available.

Wubbly, Wubbly, Wubbly ... circular logic my friend! You say that Energy remains the same, which is true. But that IS because 'energy' is a mathematical abstraction. You are looking at the results of a spreadsheet that performs the calculation "1/2 mass x velocity squared" - and somehow this is supposed to prove that Energy is something other than a calculation ... how?

The 'real' observables are Velocity and Mass. What mathematical tricks we play with these 'real' values is up to the observer, but it doesn't make them anything more than the product of a calculation.

Energy is defined as the ability to perform Work. Work is defined as the ability to consume Energy. (check Wikipedia if you don't believe me). Self referencing circular logic. Yes - the maths always adds up, because this is a mathematical game we can play.

You seem so entranced with the concept of Energy that you are willing to dismiss Momentum as having value. That I find rather silly.

Fact: Momentum is a conserved quantity.
Fact: the Momentum of a large mass can be transferred to a lighter mass, which then experiences a proportional velocity increase.

Energy is a very nebulous 'thing'. We say that energy can be transformed from one type into another - but we then have to invoke the concept of different forms of 'usefulness' of this energy. E.g. - Heat energy is a low grade form of energy, because we can't easily turn this back into other forms of energy without huge losses. Motion is a very high value form of energy - and obviously fast motion is favoured over slow motion, because of the mathematical trick of squaring Velocity.

All i'm saying is don't underestimate the value of huge surpluses of Momentum that can be created with an Atwoods. Mass and Velocity are real. Force and Time are real. Math tricks have their place, but should not be confused with reality.

[Wubbly]

greendoor,
We obviously have very different viewpoints on these issues. I see things one way and they are clear to me, you see things differently that are clear to you.

Tell you what, you can build designs that take advantage of momentum, and I'll build designs that take advantage of kinetic energy, and since we will be exploring two different paths, the probability of someone finding something will be increased.

[pequaide]

Wubbly quote: “Viewing the experimental results, you can see that the theoretical momentum keeps increasing while the kinetic energy does not. Extrapolating the results to extremes, one can see that as the acceleration gets closer and closer to zero, the momentum still keeps increasing. It doesn't seem logical to assume you can get more and more out of something that is accelerating less and less. As the acceleration approaches zero, you get virtually infinite momentum. If momentum measured the capacity to do work, you could get almost infinite work out of virtually no acceleration. No matter how deep a thinker you might be, it would not be logical to conclude the increased momentum from this experiment could lead to increased work or energy available.�

Well; it is called F = ma, so I guess according to you Newton is illogical.

For the same force over a unit period of time you get the same change in momentum; it doesn’t matter if the mass is large or small. Because a = v/t = change in velocity over change in time; then Ft = mv. If you apply the same force for a greater period of time you get more momentum, the momentum produced is in proportion to the difference in time.

Wubbly quote; “With an elastic collision, momentum is conserved and kinetic energy is also conserved. So there is a condition where kinetic energy is conserved.�

Laws are true all of the time, not some of the time.

[Wubbly]

I thought an experiment with measurable results would make things clear. Apparently it didn't to those with differing points of view.

pequaide,
The quote was referring to momentum, not force. The quote does not imply Newton was illogical. Perhaps you missed the point of the statement. It said "IF momentum measured the capacity to do work ...". You can't get infinite work out of zero acceleration, so the logical conclusion is that momentum does NOT measure work.

If you apply the same force for a greater period of time you get more momentum, ...

I agree with this. I'm not saying the momentum is not increasing. I'm saying the available work or energy is not increasing. The experiment shows this.

If you believe you are getting excess energy from your Atwoods by transferring the momentum to a cylinder and spheres and measuring the output velocity of a smaller mass, you can easily calculate the output energy in Joules by using the formula of 1/2 m v^2. I believe you have done these precise output measurements. How are you measuring the input energy, in Joules, of your Atwoods machine that you are comparing your output to?

[greendoor]

Wubbly - the Atwoods step is NOT where the overunity Energy gain is created. You can see that the Atwoods process CAN generate large amounts of Momentum (potentially tending towards Infinity as you say).

The heavy/slow momentum must be transformed into light/fast momentum before we see the Energy gains that you are hoping to see. Add another column into your spreadsheet and then you will see.

Say you have 1000 kg*m/s Momentum in a 1000 kg mass, the Velocity is 1 m/s
The Energy of this system is 0.5 x 1000 x 1 x 1 = 500J
Say you transfer all this Momentum to a 1 kg mass - the Velocity now jumps to 1000 m/s
The Energy of this system is now 0.5 x 1 x 1000 x 1000 = 500000J

The Momentum has been conserved - it is the same in both cases. But the Energy calculation has gone ballistic.

Even if we use the inferior Bolas method and can only transfer half the Momentum to the 1 kg mass:
Velocity becomes 500 m/s
Energy becomes 0.5 x 1 x 500 x 500 = 125000J - still a massive increase in Energy

The input Energy is the raising of the driver mass, which can be much less than the Energy generated.

[Wubbly]

Say you transfer all this Momentum to a 1 kg mass ...

This is where the hole is. I don't believe this is happening or can be done. You do believe this is can be done.
In pequaid's experiments, the input number for energy is never measured. The experiment is based on the assumption that since momentum is a conserved quantity, momentum is being conserved.
Energy is also a conserved quantity. If the laws of physics had to choose between conserving momentum or conserving energy, my guess is they would choose to conserve energy. Your guess is they would choose to conserve momentum. Until the input energy is measured, your scenario is not a theory, it is a hypothesis with incomplete measurements to support it. Where are the experimental proofs showing the input energy measurements of your hypothesis? There are none.

If you try to tap into the momentum of an Atwoods, IMO you can't get to it. You tap the energy instead. IMO the Atwoods is irrelevant. If you transfer the 'movement' of an Atwoods to a cylinder and sphere's experiment, my guess is that is transfers the energy and not the momentum. Without input energy measurements there is no way to know for sure.

[Wubbly]

This is a magical black box that can conserve 100% of the momentum and give it to any size mass, or conserve 100% of the energy and give it to any size mass.
In this example, your output velocity can go up by over 30 times, and you still wouldn't know whether momentum was being conserved or energy was being conserved.
Without output and input measurements, you can not conclusively determine what your black box is doing.