Recent content by Erfan

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    F = MA Contest and physics olympiad prep

    How can I find the F=ma tests? They might be good for practice
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    Book Choice for the Physics Olympiad

    Thank you for your guidance! I'm downloading the problems of Canada and I should find the other two.
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    Undergrad Intro. to Differential Equations

    So the question should be solved numerically using the Lambert's W function? I mean that can't we then have a function in the form: y=f(x)? or we can no more go further than the Lambert's W function?
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    Undergrad Intro. to Differential Equations

    I had to solve a first-order nonlinear ODE which led me to a this equation.how can I find the solution for y? yey=f(x)
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    Book Choice for the Physics Olympiad

    Hello everyone.I'm new here! and I do study for the Physics olympiad,too.I have finished all the chapters of FOP.and so I'm studying Classical Mechanic-Daniel Kleppner ,Jerry B. Marion and Electrodynamics-Grifits.But I wanted to ask where can I find national physics questions of USA and China(in...
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    Rain Drops falling down in a uniform cloud

    We have no air resistance force.But it might be possible to find a solution when the air exerts linear resistance force.
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    Rain Drops falling down in a uniform cloud

    Homework Statement Consider a uniforms cloud of density ρ1 which consists of many little drops that are approximately still.Consider a special rain drop that is a little more bigger than the others so that it starts to fall down.Water drops stays spherical all the way.But the radius gets...