Recent content by jrk012

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    Three point charge in a plane (electricity in physics II)

    I guess it would be k[Q1Q2/r1r2] = k[-5] = -4.50x10^10 J, but I tried that and its positive counterpart as well and neither are correct.
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    Electron Approaching a Charged Sphere

    SammyS, you are a saint. Thank you!
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    Three point charge in a plane (electricity in physics II)

    Homework Statement Three charges are located in the x-y plane (see plot below), with Q1 = -6.00 μC, Q2 = 5.00 μC and Q3 = -3.00 μC. Note that the charges are located at grid intersections points. *I couldn't put the grid on here, but the points are Q1 = (-2,-4), Q2 = (-2, 2). and Q3 = (3...
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    Electron Approaching a Charged Sphere

    Homework Statement An electron starts from rest 2.80 cm from the center of a uniformly charged sphere of radius 1.83 cm. If the sphere carries a total charge of 1.01×10-9 C, how fast will the electron be moving when it reaches the surface of the sphere? Homework Equations UI + KI =...
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    Sums of Independent Random Variables

    They said "Hint: V=Y" so I wasn't sure if that was supposed to be assumed known or if there were different ways to do it. Sorry I forgot to put that in there!
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    Sums of Independent Random Variables

    Homework Statement So, I know the pdf for independent random variables is found by using the convolution; the pdf is f[sub:X+Y](a) = ∫ f[sub:X](a-y)f[sub:Y](y)dy, but can I just use the density function for a function of a random variable instead; that is: f[sub:X+Y](x[u,v], y[u,v])(Jacobian...
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    Linear Algebra Proof on Composition of One-to-One Functions

    Homework Statement Prove that the composition of one-to-one functions is also a one-to-one function. Homework Equations A function is one-to-one if f(x1)=f(x2) implies x1=x2. Composition is (f*g)(x)=f(g(x)). Proof-based question. The Attempt at a Solution A...