Recent content by PsychoDash

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    Calculating the magnetic moment of an electron

    The assignment has already been turned in. I ended up just not using the given formula. Got the correct answer, even if not really in the correct way. Thanks though.
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    Calculating the magnetic moment of an electron

    Homework Statement Assume that an electron is a sphere of uniform mass density \rho_m=\frac{m_e}{\frac{4}{3} \pi r_e^3}, uniform charge density \rho_e=\frac{-e}{\frac{4}{3} \pi r_e^3}, and radius r_e rotating at a frequency \omega about the z-axis. m_e=9.109*10^{-31} kg and e=1.602*10^{-19} C...
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    Diagonalizing a matrix using perturbation theory.

    How does that help diagonalize H?
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    Diagonalizing a matrix using perturbation theory.

    That's what's throwing me off. There is no "physical system" as I have come to understand it. All I'm given is what I wrote above. I understand that to calculate perturbations in general, you use <Psi|H'|Psi>, but that gets me back to needing a wavefunction to operate on. All I have is this...
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    Diagonalizing a matrix using perturbation theory.

    Homework Statement Consider the following Hamiltonian. H=\begin{pmatrix} 20 & 1 & 0 \\1 & 20 & 2 \\0 & 2 & 30 \end{pmatrix} Diagonalize this matrix using perturbation theory. Obtain eigenvectors (to first order) and eigenvalues (to second order). Ho=\begin{pmatrix} 20 & 0 & 0 \\0 & 20 & 0...
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    Stellar Astronomy - Measuring surface temp of the Sun

    Homework Statement "Determine a surface temperature value for the Sun from the angular diameter of the Sun and the solar constant." Homework Equations L=4π(R^2)σT^4 The Attempt at a Solution At this point my only stumbling block is I don't understand the relationship between the solar...
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    Magnetic Force on a Current Carrying Wire

    You're doing the right hand rule incorrectly. Your thumb needs to be pointing in the direction of the magnetic force. When you do this and orient your fingers to point in the direction of i in the picture, you will see that they curl down, in the -y direction.
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    Coulomb's law, R is the inverse to F?

    As far as graphing, you need to recognize that F is a function of r, F(r). So you treat r as you would any variable and graph it with the values for k and q given: http://www.wolframalpha.com/input/?i=Plot%5B%28%28%288.988%C3%9710^9%29%2817*10^-9%29%289*10^-9%29%29%2F%28r^2%29%29%2C{r%2C0%2C25}%5D
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    Complex Integral Evaluation: Solving an Integral Using Cauchy's Residue Theorem

    Oh bah. And humbug. And whatever other appropriate phrases one uses when they've forgotten something basic.
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    Complex Integral Evaluation: Solving an Integral Using Cauchy's Residue Theorem

    3 terms? I see only two. 1-z^3=(1-z)(z^2+z+1) but the second term is not factorable.
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    Complex Integral Evaluation: Solving an Integral Using Cauchy's Residue Theorem

    I realize that. My question is, am I right in saying that there are no residues? I'm thinking this is some form of a "residue at infinity" example, in which case there are new rules, but I don't understand this enough to tell.
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    Calculus Help - Polar Coordinated

    In terms of the functions x and y, slope=y'/x' y'(\theta)=f(\theta)*Cos(\theta)+f'(\theta)*Sin(\theta) x'(\theta)=-f(\theta)*Sin(\theta)+f'(\theta)*Cos(\theta) Divide y' by x', switching the order of terms in x', and you have the given expression for slope.
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    Complex Integral Evaluation: Solving an Integral Using Cauchy's Residue Theorem

    Ok, I've had an idea. If I let x=z3, then the denominator becomes 1-x. Nice, since the series representation of \frac{1}{1-x} is well known. Now I'm just not sure what this change of variable does to the numerator. z5=z3*z2, but I'm not sure how to write z2 in terms of z3. My brain fails...
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    Derivative of f(t) = te^(2-7t)

    You are correct in saying that the product and chain rules are needed, however you neglected to apply the product rule. f(t)=t*e2-7t f'(t)=t*d/dt(e2-7t)+d/dt(t)*e2-7t
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