Recent content by chewwy

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    Current Flow in a Wire of Uniform Conductivity s

    Homework Statement current flows in a wire of circular cross-section, made of a material of uniform conductivity s. show the current is distributed uniformly across the cross-section.Homework Equations This should follow easily from the maxwell equations and j=sE i assume... The Attempt at a...
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    Why is F a function of the similarity variable in dimensional analysis?

    just because a quantity is dimensionless does not make it constant - it's a function of t!
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    Why is F a function of the similarity variable in dimensional analysis?

    I can get to the fact that F must be a function of (\frac{\theta_0}{kt})^a (\frac{x}{\sqrt{\lambda t}})^b but then I'm stuck...
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    Why is F a function of the similarity variable in dimensional analysis?

    Just read this, and got a bit confused when trying to do it...Homework Statement We have a diffusion equation situation with a semi-infinite rod, so: \frac{\partial \theta}{\partial t} = \lambda \frac{\partial^2 \theta }{\partial x^2 } at infinity the rod is at some fixed temperature...
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    Graduate What is the Relationship Between Energy and Time in Different Frames?

    okie doke. thanks everyone!
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    Graduate What is the Relationship Between Energy and Time in Different Frames?

    something which seems so fundamental that i can't find anywhere that derives it is the following: E' = gamma * (E - p.v) where E is the energy in one frame, p the momentum, v the relative velocity of the other frame, and E' the energy in the other frame. i.e. energy transforms like...