Recent content by zhuang382

  1. Z

    Gaussian Distribution of Ideal Gas

    My attempt : $$P(n) = \frac{1}{\mathcal{Z}} Exp[(n\mu -E)/\tau]$$, use $$\lambda = e^{\mu/\tau}$$, then the distribution can be written as $$P(n) = \frac{1}{\mathcal{Z}} \lambda^nExp[-E/\tau]$$ Note that the average number of particle can be written as $$<N>= \lambda \partial \lambda ( log...
  2. Z

    Tackling Boundary Conditions in Python (Griffins Example)

    How to run a numerical simulation of Laplace equation if one of the boundary condition is like this: $$V(x,y) = 0 \text{ when } x \to \infty$$ I am trying to use Python to plot the solution of this Example 3.5. in Griffins EM
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    Boundary Value and Separation of Variables.

    If the boundary condition is not provided in the form of electric potential, how do we solve such problem? In this case, I want to use ##V = - \int \vec{E} \cdot{d\vec{l}}##, but I don't know how to choose an appropriate reference point.
  4. Z

    Question about the classic Image Problem

    So we are actually interested in the region that ##\{(x,y,z)| z > 0, (x,y,z) \neq (0,0,d)\}##? Or a singularity at ##z = d## do not violate ##\nabla^2 V = 0##?
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    Question about the classic Image Problem

    I am studying the classic image problem (griffins, p. 124) Suppose a point charge ##q## is held a distance ##d## above an infinite grounded conducting plane. Question: What is the potential in the region above the plane? boundary conditions: 1. V = 0 when z = 0 (since the conducting plane is...
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    Delta function for \nabla(log s), where s = \sqrt{x^2+y^2}

    My intuition for this problem is to use divergence theorem: ## \int_V \nabla^2 u dV = \int_S \nabla u \cdot \vec{n} dS## But note that ##\vec{n}## is perpendicular to x-y plane, and makes ##\int_S \nabla \ln s \cdot \vec{n} dS = 0## If we take laplacian in polar coordinate directly, then...
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    Landau vol.1 Mechanics: Expansion of L' and Dependence on Velocity

    Actually, this is chapter one, so I don't know yet. I am just beginning using this book to review the content I learned last semester. I am mainly confused about the mathematical technique he uses, ( expand the Lagrangian as a power series of ##\epsilon##) when he analyze the difference of two...
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    Landau vol.1 Mechanics: Expansion of L' and Dependence on Velocity

    Let ##K## and ##K'## be two inertial frame, If K is moving with infinitesimal velocity relative to ##K'## , then ##v' = v + \epsilon##. Note that ##L(v^2) - L(v'^2)## is only a total derivative of a function of coordinate and time. (I understand this part) Because ##L' = L(v'^2) = L(v^2 +...
  9. Z

    On Landau vol.1 Pg.5 (Question about conclusion drawn by Landau)

    I understand that d/dv(L) = constant, and L is only dependent on v, but how do we get to the fact that v = constant?
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