Wheel acceleration...

[evgwheel]

ovyyus
Looking forward to see your electric motor with a sticky tape rotor.

[bluesgtr44]

...not yet!

[rlortie]

What do you mean magnets do not cause work!

Ever since the metal refrigerator and the word magnet were used in the same context, magnets have been the source of work in the form of debate ever since. Many of trees have been fell to make paper, to write books as to why magnets do not do work.

They must be a force or a form of energy as they certainly do create a lot of work even if it is in the form of typing this stupid post!

Please do not tell me that magnets do not cause work to be performed! :-)

Ralph

[ovyyus]

Ralph, I'm not exactly sure what you're talking about, however, I am sure that you do know that work is defined as force times displacement: W = F*d. In the case of the magnet stuck to the frig there is obviously no displacement taking place, therefore there is obviously no work being done.

Evg, your logic escapes me.

Steve, when?

[rlortie]

Bill,

All in jest! yes I know the definition of "work" and yes I agree that a magnet stuck to a refrigerator is not performing work. On the other hand it certainly creates work when I try to stick it on my sheet rock wall, the same wall that will retain the sticky tape!

Parlor trick time; Tie a paper clip to a 24" piece of thread or light twine. Hanging on to the free end gently lower the paper clip over a magnet sitting on your desk top. length of thread may vary. Do not use monofilament fishing line!

You will note as the paper clip gets closer to the magnet it will begin spinning! It wll accelerate for short period time, slow and then change directions. Is the magnet performing work causing the paper clip to rotate like a rotor in an electric motor?

Answer will be posted after those interested have had time to think about it.

Ralph

[evgwheel]

This is my last post on this subject as lateral thinking by an amateur is a No, No.
A seeking mind or possible additions to laws does not seem to be tolerated, as what are our beliefs/feelings, especially if they seem to question actual facts as we know at present. And I thought we were searching for the (impossible, as known at the present time). The attachment in my opinion is a good read and relevant, if you open your mind that knowledge hasn’t stopped with Newtown or Einstein.

[Jon J Hutton]

Besslers first wheel at Gera rotated at the rim at 14.45 feet per second.
His second wheel in Draschwitz rotated at the rim at 24.55 feet per second.
His third wheel in Merseberg, rotated at the rim at 24.19 feet per second.

This tells me 3 things

1 There is alot of truth here about bessler concerning his statements.

2 He was telling the truth when he said he had two wheels that worked on different principals. The times for the second and third wheel are almost exactly the same.

3 A wheel spinning at 24 feet per second will not allow a weight to be dropped on the descending side. Meaning that the weights had to be attached to a mechanism that was immune or used cf.

[ovyyus]

Ralph, as the multi-filament string is placed under greater strain it developes rotational torque (twisted twine wants to unwind as the strain increases) which makes the paper clip spin.

Nothing to do with the paper clip, nothing to do with the magnet, everything to do with the string.


EVG, I think lateral thinking is a good thing and should always be tolerated. On the other hand, being wrong about an observation presents an opportunity to learn :)


Jon, the Draschwitz wheel was uni-directional, the Merseburg wheel was bi-directional. BTW, I think weights were lifted on the descending side.

[rlortie]

Evg,

Hey! don't give up the ship over a bad vibe now and then. Thinking outside the box is what gets things inside the box.

As for the elevator accelerating, is it gravity you feel or is it inertia of your body mass????

Bill, you cheated you already knew the outcome! LOL

This swinging/ motion debate seems to be quite popular at present. I decided to track a weight on a design I am fiddling with. The following terms readily apply: Pivoting, rocking, swinging, undulation, hanging, falling, in motion, rising while swinging on a tangential path. Reminds me of some of Everts work. http://www.evert.de/eft416e.htm

Oh well what goes around comes around!

Ralph

[rmd3]

Sorry, this was discussed here eventhough it's not exactly wheel acceleration, but if someone can clarify this for me, I'd appreciate it. Something about no movement being no work done w.r.t. a magnet on a fridge. Here are my thoughts...

Two people and a rope. At each end of the rope one person is pulling with equal force to the other at the other end. No net movement. No Fxd. No work.

Are people saying no energy is being expended? I mean the energy expended is equal to the work (Fxd) and because no work is performed, then that means no energy expended, right?

(1) What is the energy expended in the two people and a rope scenario?

Gravity is pulling on the magnet, and the magnet is pulling on the metal of the fridge. But everything stands still... hmmmm...

(2) How does that rope scenario differ from the magnet on the fridge scenario?

Thanks,
Randall

[John Collins]

I'm with you on this Randall. This quote from my web site, 'why gravity wheels work' -

A teacher applies a force to a wall and becomes exhausted, what is the correct explanation?

Answer - This is not an example of work. The wall is not displaced. A force must cause a displacement in order for work to be done.

Mathematically there may not have been any force applied so no work was done but common sense tells me that is wrong. I’m not arguing that the formulae for calculating the work done is incorrect, just that to say no work is done without displacement may be mathematically right but instinctively I know that it is wrong.

There was discussion of this here and the consensus was that I am wrong, but I'm still convinced that the classic explanation doesn't cover the issue. The teacher in the above example will eventually collapse through exhaustion, yet no work was done. Try telling him that!

Your example of the fridge magnet sticking to the fridge but no work is done seems to me the same as gravity holding a book on a shelf, no work is done there either. As I said on the web site, as a formula for calculating work done it works well, but it doesn't cover the problem of calculating work done where no displacement takes place.

JC

[rlortie]

Randall,

2) How does that rope scenario differ from the magnet on the fridge scenario?

IMO it does not differ based on the formula for "work"... Work is measured by mass times movement times time. A Helicopter hovering is burning fuel and the low efficiency of the engine is creating heat and downdraft but the chopper is not achieving any work (my opinion) as it is not moving or displacing any mass. I believe it is if it is only the transference of fuel (mass) from the fuel tanks to the engine. The engine is not achieving any work as like the magnet once stopped it is exactly where it started.

Work is measured by many means, but the mechanical version is probably the most popular. Courtesy of Wikipedia.
http://en.wikipedia.org/wiki/Horsepower ... horsepower

Mechanical horsepower

The term "horsepower" was coined by the engineer James Watt (1736 to 1819) in 1782 while working in the performance of steam engines. This occurred while using a mine pony to lift coal out of a coal mine. He conceived the idea of defining the power exerted by these animals to accomplish this work. He found that, on the average, a mine horse could pull (lift by means of a pulley) 22,000 foot-pounds per minute. Rather than call this "pony" power, he increased these test results by 50 percent, and called it horsepower i.e. 33,000 foot-pounds of work per minute.

Assuming the third CGPM (1901, CR 70) definition of standard gravity, g, and the international avoirdupois pound (1958), one mechanical horsepower is:

1 hp ≡ 33,000 ft·lbf/min by definition
= 550 ft·lbf/s since 1 min = 60 s
= 550 × 0.3048 × 0.45359237 m·kgf/s since 1 ft = 0.3048 m and
= 76.0402249068 kgf·m/s 1 lb = 0.45359237 kg
= 76.0402249068 × 9.80665 kg·m²/s³ g = 9.80665 m/s²
= 745.69987158227022 W since 1 W ≡ 1 J/s = 1 N·m/s = 1 (kg·m/s²)·(m/s)

So the term "working wheel" is also a ploy, it is rotating but always ending up where it started, so is it actually working? My opinion is yes, as it did not take an ouside force to reset it such as required by a magnet.

Lifting a box of stones (work) and then letting it return to its origin is in my opinion no different than letting two magnets attract and then pulling them apart. Of course this will be disputed as the returning stones is accomplished not by manual means but by gravity (which is considered a conservative force) another strategem! I say if a magnet lifts and gravity puts it back, then by all definiton no work was accomplished but if a mechanical device performs the same task then it is said work was achieved?????

Ralph

[ovyyus]

Two people and a rope. At each end of the rope one person is pulling with equal force to the other at the other end. No net movement. No Fxd. No work.

Randall, flexing muscles do internal work even though the joints to which they are attached may not move. Two people pulling equally on a rope are doing work as their twitching muscle fibres constantly battle and strain (internal muscle fibre displacement) to maintain position.

[DrWhat]

The term "work" should be defined as 'doing something that is productive'.

If those fridge magnets are holding up my photos of me looking regrettably drunk at the work Christmas party, then they are doing work. (If my girlfriend sees the photos then the amount of work I need to do to get back into her good books is huge, and hence the magnet has made ME do a lot of work!)

But all jokes aside my definition of work as 'doing something that is productive' is perhaps valid. And hence the definition of what is productive can be subjective.

And doesn't a magnet slowly fade, lose it's energy after a long period of time? Is work being done such that that energy is lost. Maybe we simply cannot measure that work at a molecular level, like the muscles of the teacher burning up energy in John's example.

But then with gravity, is the Earth losing gravity to other surrounding masses? I guess not. Matter seems to maintain it's gravitational mass and hence it's gravitational attraction, but is this forever? What if gravity does lose it's attraction over eons.

[ovyyus]

If I could take work out to dinner some place nice, dine her on Duck with Mango Cheeks, talk cheap like there's no tomorrow while getting slowly pissed on a decent Cab Sav in expectation of a jolly good rogering, then I might get all romantic and believe, just for a moment, that work was "doing something that is productive" :P