Recent content by eck

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    What is the Simplified Integral for Average Momentum?

    I was looking at the problem some more, and all of a sudden it hit me. It's kind of embarrassing that I didn't see it before. If anyone else looks at it... nothing tricky is involved. It's integration by parts, but it's so obvious I didn't even see it.
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    What is the Simplified Integral for Average Momentum?

    I have the physics question along with the solution, but in the solution I don't understand how they evaluated the integral. I can't get my brower to preview TeX input, so I'm going to leave it without formatting, but you can find the problem http://web.mit.edu/8.05/probsets/ps1_v1.pdf". The...
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    Solving Probability of Particle in 2nd Excited State of Box

    the LaTeX got sort of meseed up... it should be A sin (n*pi*x/L)
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    Solving Probability of Particle in 2nd Excited State of Box

    Here's the problem I'm trying to solve: Suppose a particle of mass m is sitting in the ground state of a 1-dimensional box of length L. The length of the box is suddenly doubled, and the energy of the particle is measured. What is the probability that the particle will be found in the second...
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    Relating Radiancy to Energy Density?

    Sorry, the TeX came out wrong. It should be one-fourth times c times u (nu, T).
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    Relating Radiancy to Energy Density?

    I'm looking through some of my physics notes where we derived radiancy equations for black body radiation (Rayleigh-Jeans and Planck), and I have a quick question. In class, we went through the derivation for the energy density as a function of frequency and temperature. However, I can't find...
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    Why Do Gyroscopes *Start* Precessing?

    I was thinking about gyroscopes to me, and it became apparent that I'm really not comfortable with why a gyroscope attached to a pivot, with its axis parallel to the ground, doesn't swing about the pivot like a pendulum. I remembered learning something to the effect that it has to do with the...
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    Charged particle moving relativistically through E field

    I think I just figured it out. The quantity c^2p^2 - E^2 is not changed by the Lorentz transformation, so it seems like a good equation to start from. Since the electric field does work on the particle the energy term gets bigger, which means the momentum term must get smaller. Because the...
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    Charged particle moving relativistically through E field

    I'm not sure what you mean by the field being stationary. If you're asking if the electric field varies with time, then the answer is no. The observer seeing the electron moving past at 0.8c measures no magnetic field. In the reference frame of the particle, however, there is a magnetic force...
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    How do you pronounce the Greek letter phi?

    As a first year physics student, the Greek alphabet bewilders me. I'm sure everyone here has made the mistake of confusing a nu for a v, and yesterday I found out that I am incapable of writing zeta. However, the worst offender in my book is the letter phi. In the E&M textbook I am using (by...
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    Charged particle moving relativistically through E field

    Right now I'm taking an introductory E&M class that uses Purcell's book "Electricity and Magnetism." The chapter we're covering focuses on deriving the Lorentz force law for moving charges using SR arguments. This is confusing because we've never covered SR before, so I have a lot of difficulty...
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