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    Showing that an equation satisfied the helmholtz equation

    but the equation only uses the vector R, not phi or theta. e is only a function of r, so wouldnt it be like saying take the derivative of this function w.r.t. r, then take the derivative of a constant with respect to theta, then the derivative of a constant with respect to phi?
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    Showing that an equation satisfied the helmholtz equation

    Homework Statement Show that \epsilon(r)=\frac{A}{r}e^{ikr} is a solution to \nabla^{2}\epsilon(r)+k^{2}\epsilon(r)=0 Homework Equations The Attempt at a Solution Is \nabla^{2} in this case equal to \frac{\partial^2}{\partial r^2} or \frac{\partial^2}{\partial...
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    Coherence length and time

    o, okay, thanks a lot
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    Coherence length and time

    Homework Statement A filter is used to obtain approximately monochromatic light from a white sources. If the pass band of the filter is 10 nm, what is the coherence length and coherence time of the filtered light? The mean wavelength is 600 nm. Homework Equations c\tau_{0}=l_{c}...
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    Calculate surface mass density in the galaxy

    Homework Statement Suppose the number density of bright F dwarf stars at the Sun's radial distance from the Galactic center, varied with height above the galactic plane as: n(z)=n0 exp(-z/h) where h = 250 pc. Also suppose that the velocity dispersion of these dwarfs varies with z as...
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    Need help calculating the size of the Stromgren sphere

    Homework Statement A stromgren sphere is the sphere surrounding a star where the photons from the star can ionize the gas. So the radius of the sphere is the extent from the star in which the gas is ionized. For a fully ionized (idealized, for this question) sphere of gas, the number of...
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    What does it mean to satisfy the Schrodinger equation?

    okay, i used mathematica, i created functions for each term, did all the necessary derivatives and additions, and what i got was (2 a^2 e^2 m - 8 a h^2 pi epsilon + h^2 pi r epsilon)/(8 a^2 m pi r epsilon) this answer was close with the exception of r, everything else is a constant
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    What does it mean to satisfy the Schrodinger equation?

    okay, but quick question first \frac{d}{dr}(r^2\frac{d}{ dr}) is this line asking you to take the derivative of R, multiply it by r^2, and then take the derivative of the resulting equation?
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    What does it mean to satisfy the Schrodinger equation?

    Ok, I see. So what should I do since all the derivates and sums dont come out to a nice constant?
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    What does it mean to satisfy the Schrodinger equation?

    What does it mean to "satisfy" the Schrodinger equation? Homework Statement Show that the 2p wave functions of the hydrogen atom satisfy the radial Schrodinger eq. One of the radial equations for the 2p state is \frac{1}{\sqrt{96 \pi a^{3}}} \frac{r}{a} e^{\frac{-r}{2a}} Homework Equations...
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    Show that R satisfies the radial Schrodinger equation

    As the equation is right now, it has no theta or phi terms. Wouldnt I have to know the quantum numbers n, l, and m in order to introduce the other terms?
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    Show that R satisfies the radial Schrodinger equation

    Homework Statement Starting with \psi(r,\theta,\phi)=R(r)Y(\theta,\phi) saubstitute into the Schrodinger equation and show (using the technique of separation of variables) that R satisfies: (\frac{\hbar^2}{2m}\frac{1}{r^2}\frac{d}{dr}(r^2\frac{d}{dr})+\frac{C}{2mr^2}+V(r))R=ER(r) Homework...
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    Electron in a box, size of the box

    ooooo, i see. thanks!
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    Electron in a box, size of the box

    Yes, but I'm still not sure what he's doing.
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    Electron in a box, size of the box

    Homework Statement I have a test in my physics class on tuesday, and as a study guide, our professor gave us a sample test and the solutions. I worked through most of it, except for this one question. I don't understand his method to solving it, I was hoping you guys had a solution. I have...
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    Photon energy, momentum, and velocity

    Homework Statement Suppose one photon has an energy of 200 MeV and it is traveling along the x-axis. Suppose another has an energy of 100 MeV and is traveling along the y-axis. (A) What is the total energy of this system. (The answer is 300 MeV) (B)If a single particle has this same...
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    Particle energy and momentum in different reference frames

    i managed to get that for beta as well. but when i plug it into the transformation equations to find E', it doesnt come out to be correct
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    Particle energy and momentum in different reference frames

    when the question says "total energy", does it mean E^2=(cp)^2+(mc^2)^2 or does it mean E=ymc^2?
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    Particle energy and momentum in different reference frames

    okay, i managed to get the velocity correct, but i still cant manage to get E' to come out correct
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    Particle energy and momentum in different reference frames

    Is the invariant some other form of the equation E^{2}=(cp^{2})+(mc^{2})^{2}?
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    Particle energy and momentum in different reference frames

    Homework Statement A particle is observed in a certain reference frame (i.e. observer A) has a total energy of 5GeV and a momentum of 3GeV/c. (a) What is the energy of the frame in which its momentum is equal to 4GeV/c. Homework Equations E'={\gamma}E-{\gamma}{\beta}(cp)...
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    Deriving taylor series for v/c and gamma

    Homework Statement The velocity of a proton relative to our galaxy is vp/c = 1-(0.5*10^20), i.e. almost one. Such protons are actually observed. When velocity it very nearly one \gamma is very large. 1/\gamma is very small. Use Taylor series to show that for v almost one we have...
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