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  1. V

    CDF of a function of 2 random variables

    Homework Statement Two toys are started at the same time each with a different battery. The first battery has a lifetime that is exponentially distributed with mean 100 min; the second battery has a lifetime that is Rayleigh-distributed with a mean 100 minutes. a) Find the CDF to the time...
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    Explaining Voltage/Current/Resistance to non-physicists

    I'm a TA for a sophmore level E&M lab course that is taught independent of the lecture. So most of my students are seeing these concepts for the first time in the lab setting (learning through discovery). Many of them are having problems visualizing the concepts of the voltage, current and...
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    Tensors index notation

    Homework Statement Prove the following relationship: \epsilonpqi\epsilonpqj = 2\deltaij Homework Equations The Attempt at a Solution All I have so far is the decomposition using the epsilon-delta \epsilonpqi\epsilonpqj = \epsilonqip\epsilonpqj \epsilonqip\epsilonpqj =...
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    Proof that e-field lines don't cross

    I understand that electric field lines do not cross and a simple explanation is that it violates existence-uniqueness. I'm thinking there is a more complete explanation out there though. I think the answer lies in the realm of dynamical systems and non-linear dynamics, but it's been a whlie...
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    NetCDF plotting tools

    I've been having a hard time finding an appropriate forum for this question let alone put it in the proper board...so feel free to move it if need be. I am writing a script that polls a specified device on a fixed interval using SNMP and archives the results. The goal is to be able to debug...
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    Variable diameter bicycle wheel

    I'm attempting to write a simple model to describe the angular velocity profile (aka angular acceleration) of a bicycle wheel for different torque vs time profiles. Where this gets complex is that it's not a normal bicycle wheel. It is a normal wheel with weights on the spokes connected to...
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    Argument with a co-worker about gravitation

    I'm having an argument with a co-worker about gravitation and need some "enlightened" advice. The argument is whether or not two objects dropped at the same time would impact the surface at EXACTLY the same time or not. I already presented the proof that when combining the law of...
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