Atwoods Analysis

[nicbordeaux]

neptune, for once I beg to differ :) (although only very slightly)

If wubbly had been using non standarized weights, that would have been a door wide open for people to jump on him for rigging results, or claiming hysterisis in the system giving wrong readings etc. Any number of things.

Still, in a sense you are right because people will jump on you anyway.

My guess would be that wubbly is fearfully short of time, and a bog standard set of weights was the quickest way to build the rig to an acceptable standard.

Nick

ps : Roberval was right if he assumed absolutely stationary mass. The other guy you mentioned, wossisname Desguilers, was just plain wrong except under certain specific conditions.

[Wubbly]

JC - I put my keywords in the "Tags" section. Other than that, maybe more recent uploaded videos take precedence on the list. I don't know.

Nic - Higher freefall results in a higher KE value. It is still a constant, just some other, larger constant.

Neptune - There's more than one way to skin a cat. That's the one I chose. Quick and easy to swap out. I can use the weights on other experiments where jugs are not suitable.

[Wubbly]

pequaide - I'm not sure I really care how long it takes to load the spring. A spring is a force, distance relashonship resulting in Joules. If I get the spring to stretch a fixed distance, is it going to hold more energy if it was stretched slowly or quickly? I don't think so. A fixed distance stretch holds a fixed amount of energy.

This experiment was trying to find the huge amounts of excess momentum in an Atwoods with increased mass.
Each experiment showed that the energy in the system was following the kinetic energy equation which showed a constant amount of energy.
Extrapolating the results to extreme values, a locomotive could be hung off of each end of an Atwoods with a 1.13 kg mass difference, and it would take the same energy to stop the system, despite the huge increase in momentum and the huge increase in time.

If the system had a momentum of 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 kg m/s, (scientific notation not used for effect), the spring would still stretch the same amount.

At some point you are going to have to take your theoretical momentum and convert it back into usable energy to reset the system. Momentum will not reset the system, only energy will. I showed an inelastic capture extracted a constant amount of energy in spite of the 149% momentum increase (thanks for the lecture 29 reference Fletcher). Maybe the secret lies in elastic capture, but you still can't get around converting back to energy to reset.

Greendoor needs to understand the significance of that last sentance.

[Wubbly]

What is that loud sucking sound? Oh, it's the bessler wheel vortex.

[neptune]

One of the things I like about this forum is the fact that we can disagree without flame wars and agro most of the time. Re the home made weights , it was just an idea. There have been times in my life when home made was the only option.
@ nicbordeaux. Re roberval and Desagulier , I believe you have achieved results here which I have yet to duplicate, But which I havesufficient faith in to do further work in the future.

[pequaide]

Wubbly; You apply the same force for a longer period of time and get the same results (kinetic energy); and you are happy with that; greendoor and I are not. You have to apply the same force for a longer period of time because there is something more there in the 13 kg Atwood’s than in the 4 kilogram Atwood’s. Okay: you can’t persuade us; and we can’t persuade you. Next experiment.

Slowly lift the right side of a balanced Atwood’s until the left side rests on the floor. Lift the right side a few centimeters more and drop it. The right side has a certain velocity when the chain comes taut; what is conserved? Answer: momentum. Why? Because the time over which the same force acts to accelerate the left mass is equal to the time over which the right mass decelerates, that which is lost by the one is gained by the other. F = ma; a = v/t; therefore Ft = mv. If it is the same time for the same force then it is the same momentum. If you change the time as you did in the spring you change the quantity of momentum (decelerated mass) removed. But the momentum had to be there in order to be removed. Ft = mv: if you double the force you double the momentum and if you double the time you double the momentum.

I have placed all the motion of an Atwood’s into the overbalanced mass, so here is a graph that you might add to your research. Place all the momentum of your various Atwood’s into the overbalanced mass and see how high that overbalanced mass would rise if given that quantity of velocity.

If the motion given to the overbalanced mass is anything other than linear Newtonian momentum then Newton’s Laws of Motion are false. Why is it so unreasonable to think that Isaac Newton is right?
I told you months ago that springs store energy and now that you have proved it you think you have discovered something.

Do you have a part number and manufacture for that double gear pillow block?

[Wubbly]

You apply the same force for a longer period of time and get the same results (kinetic energy) ...

edit - I applied the same force for a longer period of time and got an identical result in energy. yes.

...and if you double the time you double the momentum.

I'm not claiming the momentum isn't there, the question is, how to you get to it? How do you access the momentum?

I have placed all the motion of an Atwood’s into the overbalanced mass, ...

This is where the transfer from the Atwoods to your cylinder and spheres takes place. How did you do this? How did you get around the inelastic problem and transfer it elastically? How did you access the momentum increase and transfer the momentum instead of the kinetic energy, and exactly how do you know the momentum was transferred instead of the kinetic energy? Are you saying you did the transfer experimentally or mathematically?

Place all the momentum of your various Atwood’s into the overbalanced mass and see how high that overbalanced mass would rise if given that quantity of velocity.

This is where the mathematical trick comes into play. IF (notice the word "IF") you could transfer all of the momentum from a heavy slow moving object into a light object, you get HUGE amounts of energy increase. Did I mention the word "IF"?

Momentum is not a measure of the capacity to do work. Maybe I should rephrase it and say "Momentum can NOT do work".
If I have 32 kg m/s of momentum, I have NO idea how much work can be done.
If I have a 1 kg mass that has 32 kg m/s of momentum, then I can calculate the velocity, plug the mass and velocity into equations to determine how high it will go, increasing its potential energy. I need a mass, momentum combination before the momentum number is of any use.

I told you months ago that springs store energy and now that you have proved it you think you have discovered something.

What I think I have discovered so far is that the "momentum accumulation" posts in other threads on this forum are hypothetical in nature. Did I say it politely enough? (I am not saying you are the main proponent of such posts).

[Wubbly]

Do you have a part number and manufacture for that double gear pillow block?

You have to make one, but you can find the parts on mcmaster.com and click on power transmission.
The chain is quarter pitch chain (ANSI 25). It is lighter than bicycle chain, but still strong enough for simple experiments.
The bearings are 1/2" ID, 1 1/8" OD bearings, 5/16" thick, double shielded. If you soak them in gasoline or put liquid wrench on them, you can get them to spin freely.
The sprockets have a half inch bore and must accept quarter pitch chain. The larger one has 70 teeth and the smaller one has 40 teeth.
The axel is half inch threaded rod available at your local hardware store. Use at least one lock washer on each end to keep stuff from slipping.
The piece that holds the bearings is standard black pipe available at your local hardware store. I think it may be 1" black pipe but black pipe measurements are nominal. The OD appears to be about 1 1/4" and the ID is about 1". Throw it on a lathe and bore out each end to accept the 1 1/8" OD bearing. It gives you just enough metal to play with. The bore hole is slightly larger than the bearing by probably .002", and the bearings are held in place with two nuts each end.
Weld a 2"x2"x1/8" angle iron to the pipe and weld or bolt another angle iron to the other side to give it stability. Make sure the length of your angle is less than the length of your black pipe, otherwise the weld may warp your bore hole and you can throw the piece away.
To anchor it to the wood you can use 3/4" #10 metal screws. They go into wood nicely and you only have to drill a 3/16" hole through the angle iron.
This is not the one I used for this experiment, but it is similar.

[Wubbly]

Here's a closeup of the bore.

[Wubbly]

Momentum can NOT do work

I may have snapped. Now I am quoting myself.
The above statement was trying to shock people into thinking, but it may not be entirely accurate. Let me explain.
This experiment is finished and concluded, but what did it show? Various mass combinations were dropped to determine the amount of energy in the system. There was no excess energy in the system. But how did we get to that conclusion? Because the final mechanical potential energy in the spring was basically the same for each experiment.

Along the way we used various masses and varying force x time combinations. The equations show the force was constant and the time increased, so the force x time increased with each experiment. Did the force x time result in some final energy? You would have to say "yes". Did the larger force x time equate into increased energy in the system? Based on the data, I would say "no". If you could sum up this experiment with one sentance it would probably be this:
Force x time is not a valid predictor of how much energy is in a system.

These are the conclusions I would draw, but everyone is free to draw their own conclusions. I learned a lot from this experiment. Hopefully somebody else did too. On to something else.

[Fletcher]

Here in lies the problem wubbly, or perhaps I am also going mad ;7)

I don't think the concept of what a force is is entirely understood & whether it is increasing, the same, or less when time is increased or reduced - most think in terms of net force from gravity but most probably obviously for the energy quotient to remain constant [when the weight differential remains the same] then inertia comes into play to balance the books, so to speak.

Perhaps, you have a learn'ed & simple way to explain this relationship that makes sense to everybody ?

Or, I could have sun-stroke today :7)

BTW, thanks for the informative & well crafted experiments, & the conclusions drawn !

[broli]

Lol what a funny experiment. You proved planes cannot fly by building a submarine that cannot dive. This is almost like a very bad joke on pequaide work...very professional scientific conduction but looking in the complete opposite direction, real shame.

Congratulation on realizing that force x distance get conserved, I don't think anyone disagrees with that. This experiment on the other hand has nothing to do with pequaide's work. There's no momentum transfer, there's no equality of force x time in the different setups and there's no flinging masses that can hurt. I have done the experiments properly and I have seen the results pequaide mentioned in a qualitative way. Soon I'll have a technical job that will allow me to build this more professional and use photogates to get the quantitative data.

[Wubbly]

Thankyou for your input. Go for it Broli. Maybe you will succeed where I have failed. More power to you!

[Fletcher]

broli's - useful to stop you brains turning to mush on wet days & stop your brains cooking on hot days - flap around a bit on windy days & can turn inside out with a strong puff.

EDIT: I shall attempt to interpret broli's helpful comments wubbly - apparently the atwoods is not the cornerstone of pequiades et al's theory - you need to have a broli device which is the rigid deployable arms equivalent of the cylinder & sphere's experiment - you set the flywheel into rotation [possibly by using the atwood technique of mass differential to cause rotation] - then, once the flywheel is rotating you let the opposed rigid arms deploy to a greater radius - this is the important bit - this has to happen very quickly so that all or most of the flywheel's momentum gets transferred into the tethered weights increasing their velocity & stopping or nearly stopping the central flywheel - this has to happen in as shorter distance as possible for maximum effect - release one of the weights & fling it as high as possible to show a gain in gravitational Pe - ideally this should be enough velocity & height to make up for the loss in Pe that was used to start the rotation from stationary, reset the device, overcomes frictional looses & for good measure do some work - beware though that you can't bounce that weight of an inelastic surface so that it has the right trajectory coz that would be like using a perfect spring, & we all know that springs capture energy & not momentum.

Just come up with an experimental apparatus that can do all those things. eh !

[pequaide]

A 19 kilogram balanced Atwood’s can be accelerated to 1 meter per second by adding one kilogram of overbalanced mass to one side and letting it drop 1.019 meters. This would be 20 units of momentum. If the one kilogram of overbalanced mass is given 20 units of momentum it will have a velocity of 20 m/sec and it will rise 20.38 meters.

The overbalanced mass rises 20 times higher than what it was dropped. Obviously you can get work out of the 19 meter difference.

I have placed all the motion of dozens of cylinders into small spheres, and I have placed all the spinning motion of disks into smaller pucks. I have placed the motion of an Atwood’s into a puck. I have posted pictures of many of these experiments and they are not thought experiments they are real. “If� does not always apply but it does for your Atwood’s. At this time you have not transferred the motion of your Atwood’s into a sphere but you easily could. The gear of the Atwood’s that is now connected to the spring could be used for the Atwood’s; and the front gear could be used to act as a cylinder and spheres machine. You might have to bolt a round piece of wood to the gear, and then wrap it with a string with a mass on the end. The Atwood’s could be stopped by a flying sphere instead of by a spring. I know this can be done because I have made similar experiments. With the mass you are using this would be very dangerous, don’t underestimate the velocity you will be getting.

You access the momentum by placing it into the sphere. The latest transfer I mentioned was a 66 gram sphere being given all the motion of a spinning 4000 gram wheel. This is a real experiment not a thought experiment. I know it is momentum because I have timed it in some experiments.

Thanks for the information on the pillow block. I will probably build the block some time.