Two errors in a one line. DecadentLinuxUserNumeroUno may not be the original AlwaysWrong, but he's doing his best to fill the much-needed gap.
His hand is a crappy biological substitute for a real support. The hand and arm muscles have to burn sugar and oxygen to stay in a "solid" - non-moving - state. It's not the kind of useful work that physics worries about.
In physics, work is force time distance. No movement - no work.
True. Sadly, you have failed to understand the principle.
-- Bill Sloman, Sydney
That's what I said but he doesn't seem to get it.
Try another analogy maybe ? Let's go with some simple DC electronics, like from when I was ten years old.
A switch is on, there is current but not voltage and therefore no power dissipated.
A switch is off, there is voltage but no current and therefore no power dissipated.
When the switch is on, of course if there is power one would assume that there is wattage used or dissipated somewhere, but not in the switch.
The switch is practically zero ohms. That is why there is no voltage across it. If it is truly zero ohms, there NEVER WILL BE.
If a coil is actually zero ohms, ANY voltage across it will ramp up to infinity current provided the source holds out that far.
The voltage initially across a coil before it is ramped up to plenty of time constants is not allowed due to the resistance of the wire, it is due to the back EMF. Once that is gone, the magnetuic field is determined solely by the ampere ^ turns.
If the wire is thinner and it has say ten ohms resistance, it will take ten volts to get one amp flowing. This is one ampere times turns.
If the wire is thicker and is five ohms, putting five volts across it will get one amp flowing. This is also one ampere per turn.
If the numbero of turns is the same, the magnetioc field is the same given the same coil dimensions. The voltage acts like leakage current and is dissipated in heat.
The current is what counts. And the turns.
In the scientific definition of work, if weither distance or force is zero, there is no work.
Electronics is a branch of the sciences so I figure we should deal with scientific definitions.
Oops, amperes * turns of course.
Wow! Someone who is fond of calling other people idiots doesn't even understand the physics concept of work.
-- Rick
Changing the current is not required to sustain the field.
-- Rick
On Tue, 11 Nov 2014 23:28:01 -0500, rickman Gave us:
YOU ARE an idiot. You make things up and tout them as facts.
You profess about RAM and show that you know nothing and that is a fine example of YOUR utter bullshit.
So, you knowing anything about what I may or may not know about the physical realm is a big joke, you pathetic worm.
You are not qualified to make assessments about others, since your IQ rests firmly below 20! And certainly you are not qualified to make assessments about science or physics.
The claim concerned *the scientific definition of work* . It was correct.
Your sloppy refutation... "You are performing work as you "holding it in the air" is you overcoming the gravity of the Earth. That IS "work" performed." ... is garbage from someone who doesn't remember much from physics class.
Go the other way.
It's just a matter of applied quantum electrodynamics!
-- John Devereux
liquid helium will do the trick :)
-- umop apisdn
Replace the hand with a table. Is the table performing work too?
-- John Devereux
It is in the primary, as well. That is where the inductance of the primary comes from.
-- -TV
atement that voltage is produced when the flux changes. He hasn't expressed himself all that precisely or clearly - this is DecadentLinuxUserNumeroUno - but what he's said isn't wrong.
er than the process of sustaining it.
If
rent flowing through a superconducting coil.
DecadentLinuxUserNumeroUno did say "makes the field", not "sustains the fie ld".
-- Bill Sloman, Sydney
On Tue, 11 Nov 2014 22:11:46 -0800, Dog Bagfood Gave us:
Is there work performed if a mass is raised by a counterweight at the other end of a lever and a fulcrum. Placing the weight causes the motion. Once the weight is raised, it becomes stationary.
Was "work" performed in lifting the mass to its current resting point?
In the case of the human, was work performed to place his arm in the position it is in,holding the mass, and more specifically, do you really believe that there is no "motion" taking place within his body to keep it there?
You are the idiot.
No. The earth under the table does the work supporting all of it. Not that earth, deeper. Deeper than that. More. At the center of the core, that point is doing all the work.
Cool. Hollow out that center point, and everything will float away.
Also, as you go deeper underground, gravity goes up? You are getting closer to that center point.
-- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On 11/12/2014 08:54 AM, DecadentLinuxUserNumeroUno wrote: ...
OMG!
On Wed, 12 Nov 2014 05:03:38 -0800 (PST), Bill Sloman Gave us:
A points fired ignition coil ONLY induced the HV in the secondary when the points open, and the ALREADY STANDING field collapses. That collapsing field induces the secondary on that coil to fire. When the points are closed, 12V DIRECT CURRENT gets applied to the primary, and then it becomes a static, standing field on the coil. There is no motion and so nothing is induced in the output winding.
There is a voltage produced when the points close, and the field is being established, because that does move as it occurs. But the collapsing field has such a high slew rate, that the voltage induced in the secondary is far higher than that produced were someone pumping the coil with 12 V AC.
That secondary voltage is theoretically infinite, but the spark gap loads it down, and we get around 25kV in a nice, sharp, short dwell spike placed onto our ignition plug.
So, the voltage applied to the coil creates a current through it. The current makes the filed because that is what happened when electrons move through a conductor. Stack many hundreds of turns of that field together, and we have a coil.
What makes the field?
Voltage? No. Current? No.
Work into a load? YES. WORK makes the field.
I guess that explains why it is so durn hot!
-- Rick
Anyone remember Maynard G Krebs?
WORK???!!!???!!!
-- Rick
-- Rick
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