Recent content by lets_resonate

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    Does this kind of matrix product exist?

    Suppose you have a matrix A: \left( \begin{array}{ccc} a_{1,1} & a_{1,2} & a_{1,3} \\ a_{2,1} & a_{2,2} & a_{2,3} \\ a_{3,1} & a_{3,2} & a_{3,3} \end{array} \right) And a matrix B: \left( \begin{array}{ccc} b_{1,1} & b_{1,2} & b_{1,3} \\ b_{2,1} & b_{2,2} & b_{2,3}...
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    Mathematica - Open completely separate notebook (no sharing of variable names)?

    Hi, I'm trying to learn Mathematica. Is it possible to open a second notebook in Mathematica, but without sharing variables between other open notebooks? For example, if I defined "m" in my first notebook, I want to be able to use it as just a symbol in the second notebook. I also want...
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    Evaluating a limit with l'hopital's rule

    Oh, sorry, in the context of the problem, y is a constant, so putting y^2 is a little misleading. A more accurate statement of the problem would then be: \lim_{x \to \infty} \left( \frac{x}{\sqrt{x^2+c}} \right) This doesn't change a lot. We still get those circular...
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    Evaluating a limit with l'hopital's rule

    It's been a while since I've evaluated limits, and I'm beginning to forget some of the techniques. A problem came up in physics which involved evaluating a limit of this particular form. Homework Statement \lim_{x \to \infty} \left( \frac{x}{\sqrt{x^2+y^2}} \right) Homework Equations...
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    Would running an electrical current through a magnet destroy the magnet?

    Thank you, that was a very clear answer indeed.
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    Would running an electrical current through a magnet destroy the magnet?

    Hello, Suppose you had an iron magnet. What effect would an electrical current have on this magnet? Would it still retain its magnetic properties? Thanks in advance for the help.
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    Turning a Swivel Chair: Physics Explained

    Hello, I have a beginners question about physics. Let's say that you are sitting in one of those swivel chairs - one that can rotate back and forth (about the z-axis). And let's also say that you are sitting in the middle of the room, just out of reach of anything that you can grab on to...
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    What is Force? | Force Definition

    What is "force"? Hello, As far as I know, there are two ways to look at force: 1. A mathematical shorthand for the quantity ma or \frac {dp}{dt}. Someone got the bright idea that this particular quantity is useful in explaining a particular phenomenon in nature. "The heavier something is...
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    Help with derivation - involves cross & dot products

    Gah! I got it! But I might have one more small question: \vec{ \omega } \times \left( \vec{ \omega } \times \vec{ r } \right) = \left< -\| \vec{ \omega } \|^2 x, -\| \vec{ \omega } \|^2 y, 0 \right> \vec{ \omega } \times \left( \vec{ \omega } \times \vec{ r } \right) = -\| \vec{ \omega }...
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    Help with derivation - involves cross & dot products

    Hello, I'm reading a classical mechanics book. In it, they show a derivation of the centrifugal force equation: \vec{ F_{\textrm{cf}}} = -m \vec{ \omega } \times \left( \vec{ \omega } \times \vec{ r } \right) I understood the derivation up to that point. However, they have a couple additional...
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    Possible webpage title: Defining Inertial Reference Frames in Classical Physics

    Thanks for the help guys. Through your debate, I see a lot better what the problem with my definition is. The other definition is simply more direct. My definition kind of says "A and therefore B" ("an inertial reference frame is one that does not accelerate relative to an absolute reference...
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    Possible webpage title: Defining Inertial Reference Frames in Classical Physics

    But neither is there such a thing as a true inertial reference frame. :smile: So, actually both definitions are based on fallacies. In reality, there is no absolute reference point, and there is no place in which Newton's laws are valid to their full extent. But other than that, is there...
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    Possible webpage title: Defining Inertial Reference Frames in Classical Physics

    Hello, Every definition of an inertial reference frame that I have read stated that it is a frame in reference in which Newton's laws are valid. But is it possible to define it in this way: it is a coordinate system that is not accelerating relative to some absolute reference point. Is there...
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    Help with Derivation of Centrifugal Force Equation

    Thank you for the help. I managed to derive the equation properly: \left( \frac{d}{dt} \right) _i = \left( \frac{d}{dt} \right) _r + \omega \times This "transformation" is first applied to r: \left( \frac{dr}{dt} \right) _i = \left( \frac{dr}{dt} \right) _r + \omega \times r v_i = v_r +...
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    Help with Derivation of Centrifugal Force Equation

    Hello world, I'm trying to understand the derivation of the centrifugal force equation, F_{centrifugal} = - m \omega \times \left( \omega \times r \right). I used these pages to help me in my pursuit: http://observe.arc.nasa.gov/nasa/space/centrifugal/centrifugal6.html"...
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