Recent content by thenewbosco

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    Travelling wave reactor anyone ?

    Apart from cooling and control issues, I do not understand why they would want to have the reaction propagating in one direction. Losses could potentially be minimized by having the highly enriched zone in the centre of a "slab" surrounded by breeding material. The reaction could proceed in both...
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    Easy percent composition question

    how would i calculate the mass percentage from the atomic percentage?
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    Easy percent composition question

    1. For a problem I require the atomic density of uranium atoms per cm^3 in a solution of water. The atomic fraction of natural uranium to water is 1 per 100 and the net density of the solution is 1 g/cm^3. (Natural uranium is assumed to be U-235 at 0.72% of uranium atoms and the rest is U-238)...
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    Nuclear reaction cross section

    Suppose we consider a beam of neutrons incident upon a thin target with an intensity of 10^12 neutrons/(cm^2.s). Suppose further that the total cross section for the nuclei in this target is 4 b. Using this information, determine how long one would have to wait, on the average, for a given...
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    Angular momentum quantum mechanics

    since m=-l...+l we have 2l+1, m values. how do i know which integers i will have for l in this case, would it be just 0 and 1? Since the hamiltonian has degeneracy, how can i find what else i need to specify a complete set of commuting observables?
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    Angular momentum quantum mechanics

    Consider a spin-less particle, mass M, confined on a sphere radius 1. It can move freely on the surface but is always at radius 1. 1. Write the Hamiltonian H=\frac{L_{op}^2}{2M} in spherical polar coords. 2. Write the energy eigenvalues, specify degeneracy of each state. (not you can omit r...
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    Solving a Car Vector Displacement Problem: Calculating Total Displacement

    if you take two steps forward and one step back you have gone one step forward. This guy has gone 65km east then back 45km, so he has gone 65km-45km
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    Solve Lagrangian Problem: Mass m Revolving in Circle

    Homework Statement Mass m is connected to a string and is being whirled in a circle in a horizontal plane of a table. The string passes through a hole in the center of the circle and is being pulled with a constant velocity V starting at t=0 so the radius decreases. Initially the mass is at...
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    Calculating Expectation Values for x, x^2 in 1D Box

    Homework Statement Calculate the expectation values of x, x^2 for a particle in a one dimensional box in state \Psi_n Homework Equations \Psi_n = \sqrt{\frac{2}{a}}sin(\frac{n\pi x}{a}) The Attempt at a Solution i formed the integral \int_{-\infty}^{+\infty}\Psi ^2 x dx as the...
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    Delta function integral

    so what youre saying is to form the integral f(y)=\int 2x-x^2 dx? if its outside the interval do i let the limits be (-infinity to 0) and (2 to infinity) for inside 0 to 2 but at the endpoints what are the limits?
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    Delta function integral

    let f(y)=\int_0^2 \delta(y-x(2-x))dx. Find f(y) and plot it from -2 to 2. I know how to calculate \delta (g(x)) but i am not sure how to treat it with the y. I thought possibly to solve the quadratic in the delta function to find what x will equal for the roots in terms of y and got...
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    Solving Potential Energy: Force & Potential Exam Ques.

    Just studying for an exam and the following question appeared on the sample exam: Given the force: F=-c(x-y)^2(\hat{i}-\hat{j}) where i and j are the unit vectors. a) Show the force is conservative b) Show the potential energy is given by V(x,y) = \frac{c}{3(x-y)^3)} assuming V(0,0) =0...
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    Solving the Mystery of an Unfamiliar Trig Identity

    Today the professor wrote down the following for use in an integral: \frac{1}{2}cos(2\theta)=sin\theta cos\theta i am not sure is this is correct. i have tried to prove this and cannot, i have also not found it in an table of trig identities. Is this a valid identity? i am not sure since...
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    Integrate and Evaluate Vector Functions | Circle and Straight Line Paths

    hello, i just wish to check that i have done the following correctly: 1. Evaluate \int d\overarrow{r} (r is a vector, and its a closed integral) around the circle C represented by x^2 + y^2 = a^2 what i did here was switch to polars and called d\overarrow{r} ->rd\theta then i noted that...
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    How to compute the following integral

    but for what you propose then du=2(x-xo)dx, which cannot be put into the integral like this...
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