Recent content by BrunoIdeas

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    PhD Physics Student Seeking Quant Advice

    Hi, we've been talking of salaries as 90k , 135k, etc. But is that NET salary or does one have to subtract taxes, etc. ? In such case, how much does one have to subtract? About what percentage? Thanks everyone.
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    Under what conditions does L=Iw hold?

    So, that is the question: Under what conditions does L=Iw hold? Where L,I,w are all scalars. Some specifics perhaps: 1) Supose a fixed axis of rotation, with accel, does is hold? 2) Suppose de axis of rot is not a ppal axis 3) Suppose there is fixed axis of rot, but I choose neither x nor y...
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    Inductance and AC Source: Why current?

    Hello! Two months later I re read your answer and at least I'm having a better feeling. However, maybe it is a stupid question: I can accept from Faraday's law that if flux changes from zero to some value in time t, by time t there will be a voltage induced. But what is the physical reason...
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    Why does magnetic force tend to increase magnetic energy?

    Hello. So: Why does magnetic force tend to increase magnetic energy? 1) Usually, forces go in the direction of energy minimums. Why in this case is the opposite? 2) What does it imply? What is that makes magnetism particular in some senses, for example this, for example its force function...
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    Inductance and AC Source: Why current?

    Hello. I'm am studying topics related to inductances and Faraday's law and I'm having hard time at PICTURING situations. Mental representations. So I propose an example of something I don't understand and we may go on from there. Consider circuit consisting of an inductance and an AC source...
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    Potentials which depend on positions of two particles

    Fine. Thanks, I get that. Now I would like to ask what about energy conservation in such cases. 1) Consider a mass attached to a spring hooked from the ceiling with no gravity (or with it, it does not matter). We say that energy is conserved because forces are conservative. Question: Does the...
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    Potentials which depend on positions of two particles

    I am so grateful for your answer. I particularly apreciate you've given me the intuiton about understanding conservative forces as position dependent and the notion of getting work back. Using this one evidently sees why friction is not, and probably why it conflicts with time invariance or...
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    Potentials which depend on positions of two particles

    Hello. I have been asked if it is correct to say that the force of a spring is conservative. So, for a mass attached to a spring on the roof it's OK. Now consider two masses linked by a spring. Now the potential will depend on both coordinates. It is now not so clear to me any of the...
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    Newton's third breakage in Goldstein's classical mechanics

    Hello. I have just read the passage from Goldstein's text and have the same questions. I however also question the validity of Biot-Savart Law for point charges. If someone with a thorough understanding of the topic, who has gone through the same process of learning we are, could answer, it...
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    What does the energy of an electrostatic field mean?

    Hello everyone. So that is my question: What does the energy of an electrostatic field mean? A more detailed description of my background or understanding will help you to provide an answer: The process to deduce such a thing is usually calculate the work done in order to bring charge...
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    How does mains electricity work?

    Hello. I've been reading numerous texts about mains electricity but I'm not getting some of the things. I'll start with some questions, considering Live, Neutral, and Ground wires. 1) Does the neutral wire return/come from the supply company? In that case, where does the company connect the...
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    Beginners Guide to Probability & Statistics: Examples & Applications

    What book or course would you recommend to a beginner in Probability and Statistics? That is my question. However I would like to specify my intentions. Along my math courses I have observed (many people have) that mathematicians have a different way of thinking this common language...
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    How could one measure degree of coherence with Fresnel birprism?

    How could one measure degree of coherence with Fresnel biprism? Hello. I have some questions about the study of partial coherence with a Fresnel biprism. In common text degree of coherence and its relationship to visibility is introduced considering a Young Double Slit experiment. At the...
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    How to get information on low frequencies of a signal using FFT?

    Hello. I've made a lab experiment of interference and with a CCD camera photographed fringe pattern which one can understand as a periodic signal. My question is: When I apply an FFT to the image is there any limit to the amplitude information I may get from lower frequencies? I read in the...
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