studiot

I've not come across that one before. +1

You need some EM theory to study quantum mechanics, but nowhere near third level stuff. In fact you need a similar level of basic EM viz A level to first year university to study to study either QM or EM at third level. You do not need any QM to study electromagnetics. Good luck with the OU, it is a tough route on your own.

Surely an 'Albert' would be more appropriate?

Actually since c is a constant c2 is also a constant with dimensions L2T-2

Yes I would agree that you need a three stage circuit, call them stages 1, 2 and 3, since you have to provide defined input and output filter characteristics with the rolloffs. So stage 1 for the input filter, stage 2 for the required gain, stage 3 for the output filter. The turnover points are very low in frequency and within the reach of any conceivable BJT ft so that will not be a problem and a beta of 100is pretty usual. I can't see a voltage gain (that was A?) presenting any problems either with a single BJT in stage 2. So what are your next thoughts? Edit my next thought is that you haven't stated the input voltage level. with an output requirement of Vo = 75Vin this will constrain your configuration possibilities and power supply requirements. In the light of this it may be sense to combine stages 2 and 3, perhaps as a coupled bjt pair.

+1

Interesting distinction, Timo. +1

It's a fair question about space between, if you are going with the little balls or photons model. The best way to answer this is to think of a gas. The molecules in the gas are buzzing about, but there is lots of empty space around them. The greater the number of molcules in a givne space the less the free space of course, but there really is normally much more free space than molecule, even in a gas plasma. Now there is one big difference between gas molecules and photons. Gas molecules have a range of speeds and we discuss the average speed, and the spread. Photons all travel at the same speed. But we can still talk of phton density, just as gas density. So no, continuity is not an issue with this model.

Lock Lock, who's there?

What makes you think it is broken? Many such pieces of equiment wil only turn on under load. Have you tried it on load? This could be very dangerous if you lack experience.

Is that all? I thought over 90% of folks in the US were immigrants at one time. Einstein and Emmy Noether being examples of your best catches.

Huffing and puffing creates hot air, not vacuum. I don't need paragraphs of introduction I just need you to state your case, coldy and clinically, in three lines or less.

So what was the question or proposition?

I like this +1 I'm having more trouble with this since, as I understand it, Newton didn't mention straight lines either. Again straight is one modern interpretation of "in its right line", there are others which suggest Newton was leading into geodesics. Interestingly I was looking at modules 3 and 4 (mechanics) of the London University modular A level mathematics and physics and what do you think they were analysing at high school level? You got it in one The Norton Dome, although they did not call it that.

I am puzzled where this definition comes from? The English verb to compel comes directly from the Latin com and pellare (= to drive as in forced direction) which Newton actually used and means pretty much the same thing. It does not include the change, since compulsion can be preventative as well as causative. Perhaps you meant a(p) and pellare which use is closer to your translation?

With the greatest respect if you are going to make an assertion, you need to be prepared for it to be subject to considered scrutiny and to back up your assertion if that scrutiny reveals chinks. Use of the word 'unless' asserts that there is no other cause or concurrent agent possible. However it does not assert that just because the agent is present the effect will occur either. The word compelled asserts that if such an agent is present it will act to create a stated effect. However it says nothing about the relationship in time between the two. In particular it does not preclude them being simultaneous and continuous. Nor does it preclude other (un-named) agents also being able to effect the same cause. So the discussion should not be Which definition is better ? but Why do they demonstrably not mean the same thing ?

Please display the chain of reasonsoning backing up this claim. Newton, of course, knew nothing of Wikipedia, and did not mention causality. I see nothing in the statement to require precedence of the forces over the effect. I repeat and repeat and repeat that there is a difference between the plural and singular in this comparison, because rest is involved. Furthermore The Wiki version definitely implies an effect since it states that there is no effect unless acted on.... Newton backs both horses by stating the positive....'compelled' I have noticed that in several areas of physics carefully wrought statements by truly great men have been changed by lesser men in modern parlance with the result of a problem somewhere. there are two MIT lectures on Ytube where this has happened to Kirchoff in electrical engineering and Lord Thompson in thermodynamics. Edit As a matter of interest Newton and his contempories realised that their mechanics 'fluffed' action at a distance, but they did not know how to resolve the issue (have we truly done so today?) so had to remain content that their strong statements worked at the short ranges they were concerned with. They also lweft some wiggle room and this is cutely discussed by Turner in the Routledge University Physics book Relativity Physics. Turner presents a fascinating rewrite of N1, N2 and N3 to make this compatible with the principle of relativity.

I don't get the connection. 'impressed theron' from Newton implies to me the external force in the modern version. With the exception, already noted, that Newton was specific in his use of the plural forces and the modern version only contains one force. and therefore allows the possibility of a contradiction when two or more forces in balanced opposition act on a body, producing zero effect. Such a contradiction is excluded in Newton's version. But none of this is relevent to md65536's comment.

how is 'acted upon' different from 'compelled' ?

1/36 When I went to school there were 36 inches in a yard. 1/4 is an engineering 'collection efficiency factor'. I did state this before, and assumes you can only collect 25% of the rainfall for various reasons. 18 inches per month, well I looked here and waved my guesstimate wand. http://www.costaricaexpeditions.com/AboutCR/tempchart.php

One swallow doth not a summer make nor one electron a spray. But then you asked for a spray.

Funny, my parent's TV could do just that back in the 1950s and I understand the LHC at CERN could now do it across a continent. And somewhere between the two I hear they have developed a techology called electron beam welding.

What particles please bob?

As a matter of interest since my alignment of point masses and particles caused some eyebrows to be raised. I still contend that this is the normal common or garden interpretation British best practice. Classical Mechanics : Gregory : Cambridge University press American best practice. Analytical Mechanics : Cassidy and Fowles : Saunders

lasix, from your posts, you seem to have an interest in electric/electronic experiments. This is good but you need to get some solid facts and theory behind you so you can understand and properly evaluate things you are being shown. I think legal discussion about captuing minute quantities of radio waves is a bit over the top. But Mordred has offered you some solid Physics about Ohm's and other laws. Capturing some 'free' energy from the air is easy. Farmers and gardeners do it all the time when they lay black polythene on the ground to warm it or use greenhouses, cloches etc. You voltmeter will not register anything from the light involved, but a suitable lightmeter would and black polythene is a suitable physical structure to receive it. The electric field of waves given off by wiring and of radio waves can vary enormously from a few microvolts in the remote countryside to many volts, tens of volts or even greater near the source. As I have shown you cannot draw significant power from most of these without suitable apparatus, though you can observe the voltage. For those making electrical measurements or connections these are often unwanted signals (voltages). This is why the standard connection cables are usually 50 ohms. These extraneous signals are soon cut down to size by this low impedance as the souce cannot maintain significant voltage into this low value. In my workshop I do not need a coil or special magnets, I can simply dangle the test leads of a better quality voltmeter than used in the video over the edge of the bench and see the voltage jumping around several volts until I connect it to something or use a 50 ohm connection. Any Radio Amateur or Technician will show you this phenomenon. It has been known since we had meters.