Recent content by senan

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    The resistance of electrolycra

    I was shown electrolycra recently and initially as you stretch it the resistance increases, which I think is due to the silver in the lycra not being able to shortcircuit as the lycra separates out. However if you keep stretching the electrolycra eventually you reach a critical point at which...
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    Simple pendulum and acceleration due to gravity

    So for the simple pendulum T = 2π √(l/g) and then T =1/f so f = (1/2π)√(g/l) therefore f is proportional to g for a pendulum with the same length. Wouldn't the frequency then decrease when g is decreased? For the mass spring system the formula is independent of g so I can see why it has no...
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    Simple pendulum and acceleration due to gravity

    Homework Statement A simple pendulum and a mass-spring system have the same oscillation frequency f at the surface of the Earth. The pendulum and the mass-spring system are taken down a mine where the acceleration due to gravity is less than at the surface. What is the change in the frequency...
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    Pincushion distortion from spherical detectors

    I'm wondering how the use of spherical shaped detectors causes pincushion distortion. I can understand the shape of the detector affecting the final image but I thought the lines would bend out as when a hemisphere is laid out flat, a point appearing near the center from the front on angle would...
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    Understanding Markov Processes & Stationary Distributions

    Homework Statement Consider a Markov Process X(t) over discrete set omega = {-1,0,1} with transition probabitities W(-1 | 0,t)=W(0 | -1,t)=W(1 | 0,t)=W(0 | 1,t)=d a) What is master equation b) Find the stationary distrubtion Ps(x) for x element of {-1,0,1} The Attempt at a Solution a) the...
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    Mathematica modelling question

    Thanks for ye're replies. I think I'm going to have to go back and try and simplify th system a bit it. Hopefully I can reduce it down further by adjusting a few terms
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    Mathematica modelling question

    I'm kinda of messing around with a model of a biological system, I've found the equilibriums and decided I'd get the stability relations as well. I tried using mathematica to get the eigenvalues of the system to see if its stable or not and when I got the eigenvalues of my matrix mathematica...
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    Solving Cauchy Problem: General Solution of xy3zx+x2z2zy=y3z

    Homework Statement getting gen sol of xy3zx+x2z2zy=y3z solve cauchy problem x=y=t, z=1/t The Attempt at a Solution i got gen sol F(C1,C2)=0 as C1=x/z, C2=y4-x2z2 i inserted t for x and y and 1/t for z and ended up with C1-2=1/(C22) I'm unsure what to do from...
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    Kinetic energy of alpha particle during decay

    Homework Statement Show that kinetic energy acquired by an alpha particle during an alpha decay is Talpha=Q/[1+[maplha/mD] Homework Equations Q=[mP-mD-malpha]c^2 The Attempt at a Solution Q is the release of energy which is acquired by the daughter nucleus and the alpha...
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    Entropy change of liquid water

    Homework Statement Find the change in the entropy of 250 g of liquid water at its boiling point when it is vaporised at a pressure of 8 atm. Give a brief physical explanation for how this entropy change compares with the entropy change for vaporisation at 1 atm pressure Homework...
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    Simple but poorly worded unit conversion question

    As I read the question I just see it as your 3rd point. The sum of the gain of each of the days is simply 54ms. As the question gives you the increase per century independent of the length of the day I don't see why you are involving sumations at all. The increase per century is 1ms independent...
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    Quantum Mechanics uncertianty in momentum

    Homework Statement A neutron star has a core composed of protons and neutrons (nucleons) and has a density higher than the nuclear saturation density ns = 0.16 fm ^−3 . (i) [6 points] Assuming nuclear saturation density throughout the core, calculate the uncertainty in momentum for a...
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    Thermodynamics perfect gas Question

    Homework Statement The partition function for a perfect gas containing N monatomic particles of mass m at a temperature T is Z =(1/N!)*VN[2(Pi)mkT/h2]3N/2 (2a) Use this partition function to find the molar Helmholtz free energy, molar internal energy and molar heat capacity at constant...
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    Partition Function Homework: Find Entropy Change for Isothermal Expansion

    Homework Statement One mole of a gas obeys the equation of state (P +a/V2 )(1 −b/V) =RT/V Find the change in entropy if one mole of the gas is isothermally expanded until the volume is doubled. Express your answer in terms of the initial volume of the gas Vi. Homework Equations S2-S1=1/T...
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