Manipulating Momentum

[Trevor Lyn Whatford]

Hi Greendoor, the eyes do not lie, you can see there is more work do against gravity than the my lifting of the pendulum, when this is mapped out its a lot more lifting against gravity than my one lift, explain it how you will but the fact is there is more lifting against gravity than my the first lift, it is the efficiency of the pendulum that makes them so useful for energy and speed control release, there is no OU output wise, but there is over unity in the lifts against gravity! you have to admire them for that.

Trevor - Work is a lot like money. You can convert money from one currency to another as many times as you like, but the bank will want to take a little cut each time. So eventually you will lose all the money if you keep doing it.

You input Work into the pendulum when you apply Force over Distance as you raise the pendulum bob against the force of gravity.

When you drop the bob, the potential Energy is converted into Kinetic energy. Once it reaches the bottom of the swing, it has then converts the kinetic energy back into potential energy. Then repeat, until all the energy has been lost as heat & sound.

The positive Work is reversed by the negative Work. The rising is reversed by the falling, etc, etc.

there is no OU output wise, but there is over unity in the lifts against gravity!

There is no return on your investment energy output wise like I said in the above quote, but there is a large return on your investment when it comes to non-useable lifts against gravity, and its kinetic energy thereof, unless like me you like to see it swing and count and measure the heights of its swings that is, and watch kinetic energy being converted from gravity, maybe even time my lift of the pendulum and then time how long it take to stop, then just ponder at why other tell you it is not happening and there is no kinetic energy increase, and that I lack basic Physic knowledge? I have the Knowledge, I just like to question parts of it that does not quite ring true! and a pendulum is one of then, natural law preventing PM another, natural law Less than 300 hundred years old! PM Earth 13 billion years old, just how long a timed experiment do you need before you question parts of physic?

Regards Trevor

Correct spelling none to non- useable, thank you Greendoor.

[greendoor]

There is no return on your investment energy output wise like I said in the above quote, but there is a large return on your investment when it comes to none useable lifts against gravity, and its kinetic energy thereof, unless like me you like to see it swing and count and measure the heights of its swings that is, and watch kinetic energy being converted from gravity, maybe even time my lift of the pendulum and then time how long it take to stop, then just ponder at why other tell you it is not happening and there is no kinetic energy increase, and that I lack basic Physic knowledge? I have the Knowledge, I just like to question parts of it that does not quite ring true! and a pendulum is one of then, natural law preventing PM another, natural law Less than 300 hundred years old! PM Earth 13 billion years old, just how long a timed experiment do you need before you question parts of physic?

What do you mean by "none useable lifts against gravity"? Non-useable maybe?

You contradict yourself when you say that you have physics knowledge, but that you can watch an oscillating system depleting itself of kinetic energy and still be wondering if perhaps the kinetic energy could be increasing ....

It is NOT increasing. The longer it takes, the slower it is depleting, but you are basically just watching all the energy your put into the system slowly being turned to heat. And if you tried to remove some energy for useful Work, it would very quickly come to a stop.

[Grimer]

No need for the sarcasm, Nic.

I was merely pointing out that your statement that conservation of momentum "exists in theory only" is incorrect.

[nicbordeaux]

My unreserved apologies Frank. 'Twas intended more as a pun than an attempt to cut.

Still, a lot of the cases described or discussed show in theory or calculations all this massive qty of momentum in objects which experiments show have come to rest. Anyway, forget it, I am but a poor farmer, what do I know about momentum ?

[Trevor Lyn Whatford]

Hi Greendoor,

your quote,

It is NOT increasing. The longer it takes, the slower it is depleting, but you are basically just watching all the energy your put into the system slowly being turned to heat.

My lift energy was work against gravity and gravity must have been working against me, that was my input, As soon as I let go of the weight gravity takes over, and gravity is then the energy provider, this is the bit I like watching the best, to see gravity trying to conserve its input and creating non-conservative energy in the process! it reminds me that in 13 billion years just how much friction gravity has been working against to sustain the Earth's orbit there must of been some non-conserving work from gravity as well, or we should have stopped by now, friction less space forget it, look at the state of the moon.

Regards Trevor

Edit add from gravity.

[Trevor Lyn Whatford]

thinking about it though there most be more kinetic energy in use than the kinetic energy used for the first lift of the weight, none of it useable as a output though, it makes me wonder how efficient a airfoil pendulum would be, has anyone here tried it? maybe have it swivel mounted and a vain to turn it for its opposite swings.

Well Trevor, your best bet might be a set of glider wings, the angle of which you could modify. At what point you'd want them to give maximum lift, no idea. Obviously, the lift gain would have to be more than the drag loss.

Or hang on, you could have a airtight room (wear diving gear and bottles, oxygen stravation does funny things to the brain) and on the first swing, which is where you get the maximum height you'll ever get from a non-winged pendulum, you have a OB wheel with a whopping mag on it. Pendulum (ferrous bob) get's a few mm rise from mag attraction and sticks to pendulum, wheel does a full turn and you have gained a little height because the wheel is slightly oval. You could ust as easily gain the height by not bothering with a pendulum and lowering a big mag until it picks up a steel object on the floor then oscillates very moderately in a pendular manner (it will), but so what, hey ?

Even better, you could have a pendulum swinging from a rather large lighter than air filled baloon.

Let us know how it turns out. Might be some fun to be had flying mammoth kites with 10 kg pendulums on 'em.

I was on about increase efficiency not OU, but next time I land sail at over 30 MPH in less than 10 MPH wind I may think more about it, you would not get a 360 out of it but you may get close to a 180, it maybe worth a look at the blade tip speed on a large wind turbine, I think a weight out of balance would turn the wing better, or maybe my reversible wing design, when you look at that green monster pendulum they are trying at the minute, they need every little bit of help they can get.

With thanks Trevor

Edit, change wind to blade, and sail to wing.

[Kirk]

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Fletcher wrote:

There is no Conservation of Kinetic Energy Law that I'm aware of ...

Fletcher, In an elastic collision, kinetic energy is conserved. At 3:03 into this video, http://www.youtube.com/watch?v=H9otEyp14q0 Professor Walter Lewin states this.

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... I have better things to do ...

If I was in Fiji, I would have much better things to do with my time. :D


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This applies to elastic collisions of the first condition only.

[Fletcher]

Kirk .. what wubbly's video was saying is that Momentum & Energy are conserved.

In the case of a perfectly elastic collision [an example being the gravity assist] Ke is conserved because there are no other losses such as frictions or sound etc - he uses the 'ideal' example of two balls in collision - in practice it's impossible to fully conserve Ke in macro exchanges where an actual physical collision occurs because there is the production of heat & sound at least.

For every other type of collision event the Ke conversion is not conserved perfectly.

In the case of a perfectly inelastic collision [where two masses stick together after impact] the Ke before & after is vastly different & less - the difference being the conversion of Ke start to other forms of energy.

So, the two types of collisions form the bookends for the range of types of collisions that can occur - at no time is there Ke above start conditions, at very best it can equal it.

So Momentum & Energy [but not usually Ke] is conservative in mechanics.

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So back to your theory - you need to know the Ke of each mass set to collide - it is different from the momentum units - current physics says after collision the total system Ke will be less than or equal to the beginning Ke, but not greater.

If, by way of repeatable experiment, you can show that this is not true in all circumstances for closed systems, then you will have found a loop hole in physics understanding, no doubt exciting the momentumists & others.

This applies to elastic collisions of the first condition only.

What are elastic collisions of the first condition ? - I must have missed that.

[Kirk]

>What are elastic collisions of the first condition ? - I must have missed that.

On page 1 of this thread I listed 3 types of elastic collisions. Type 1 is with an object you would call stationary.
The literature is full of fertilizer regarding ke turned into heat and sound. The real measure of loss is loss of momentum to heat and sound. It will be quite small unless you are colliding dumplings. The ke loss is loss of velocity as ke is velocity in a new cosyume, thats all. To think it is lost energy is a failure to see itt for what it is.

If you collide 2 equivalent masses - ie a mass of 1 unit at 100 feet per second picks up an equivalent mass and now is moving 50 feet per second. No momentum was lost. What is this insanity that the missing ke is heat and sound? Until you reconciule in your mind what the missing ke represents you are stuck.

[nicbordeaux]

"If you collide 2 equivalent masses - ie a mass of 1 unit at 100 feet per second picks up an equivalent mass and now is moving 50 feet per second. No momentum was lost."

Kirk, do you have a real world example of this 100 % scenario ?

[Kirk]

As near as the physics textbook on your shelf.
they will discuss this then quote you
m1v1=m2v2
equivalence

1x 100= 2 x 50

[murilo]

Energy can not be loosed and everybody knows this!
We all are hoarse of so much listen to this... 8)
BUT energy can be transformed and everybody should know this!
Transformed as heat, sound, infra sound, cracks, micro cracks, mass deformations, mechanic vibrations...
Question to inventor and designer is to manage this transformation, since it IN PRACTICE appears in the system as LOSSES...
( kind of engineered game of words. 8)
Best!
M.

[nicbordeaux]

As near as the physics textbook on your shelf.
they will discuss this then quote you
m1v1=m2v2
equivalence

1x 100= 2 x 50

Well, we can I guess all agree that the physics , on this particular issue of total transfer during collision, is pure theory for a theoretical world. And as Murilo points out, the difference between theory and realiyu are losses or dissipation, or I would add, imperfect collision.

[Mark]

My two cents worth:

When it comes to transferring momentum, impulse is superior to impact.

[Kirk]

As near as the physics textbook on your shelf.
they will discuss this then quote you
m1v1=m2v2
equivalence

1x 100= 2 x 50

Well, we can I guess all agree that the physics , on this particular issue of total transfer during collision, is pure theory for a theoretical world. And as Murilo points out, the difference between theory and realiyu are losses or dissipation, or I would add, imperfect collision.

Qf course nothing is 100% by definition but when we discuss mechanisms we restrict the conversation to first order effects. But to obfuscate because it isnt 100% isnt realistic. I point out a head on collision at 60 miles per hour will break your car and you want to discuss how acrylic versus enamel paint makes it different.
Sheesh!