Recent content by Pi-Bond

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    What Forces Act on a Train Carriage Moving Along a Bend?

    But if the tensions are perpendicular to their radial vectors, how can they have a radial component?
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    What Forces Act on a Train Carriage Moving Along a Bend?

    I'm unsure about how to get the radial component of the tension. Anyway here is my understanding of the geometry of the situation: Is this correct? FT refers to the force due to the tracks. The centripetal force required by the car is \frac{MV^2}{R}
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    What Forces Act on a Train Carriage Moving Along a Bend?

    Oh sorry, I wrote the wrong formula in haste. What I meant was F_5 = \frac{F}{5} F_4 = \frac{2F}{5} and so on. Also I noticed I didn't say that we have to find the velocity for which the rails exert minimum force on the central carriage. Sorry about the confusions. So in order to...
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    What Forces Act on a Train Carriage Moving Along a Bend?

    Homework Statement A train consists of a locomotive and five identical carriages, connected via massless ropes. Initially the train is moving at a speed V. At this speed, the tension in the rope, F between the locomotive and the first carriage exactly balances the resistive drag, so the train...
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    Exploring Resistance in a Ferromagnetic Circuit

    But in the first case, one branch of the parallel circuit has two resistors of σ+ and σ- in series. In the second case one branch has two σ+ resistors in series, while the other has two σ- resistors in series. Why this change?
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    Exploring Resistance in a Ferromagnetic Circuit

    I figured out the answers. For the first part, both branches had the two resistors of either conductivity in series. For the second part, one branch had the two resistors with σ+ in series, while the other had the two resistor with σ- conductivity in series. I'm not sure why this is the case...
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    Exploring Resistance in a Ferromagnetic Circuit

    So are resistors on one side of this parallel geometry having the same conductivity? By the way this is from a comprehensive exam. Sometime we do see "historical question", but the effects are not really named!
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    Exploring Resistance in a Ferromagnetic Circuit

    Do you mean something like this?
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    Exploring Resistance in a Ferromagnetic Circuit

    Homework Statement Electrons in a ferromagnet whose spins are oriented in the direction of, or opposite to, the internal magnetisation carry independent currents I+ and I−. This leads to the material behaving as though it has different conductivity σ+ and σ− for each of the two current...
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    Electron Spectrum in Beta Decay

    Homework Statement A nucleus N1 decays through beta decay to nucleus N2. The mass difference between N1 and N2 is ΔM. The differential decay rate may be written as: dw=p(E_e)dE_e p(E_e) \propto E_e (E_e^2-(m_ec^2))^{1/2}(\Delta Mc^2-E_e)((\Delta Mc^2-E_e)^2-(m_vc^2)^2)^{1/2} where Ee is the...
  11. P

    What is the role of zero-momentum frame in two-photon collision processes?

    All clear! I understand better now, and I will keep that expression in mind. Thanks mfb!
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    Mathematics of Quantum Mechanics

    I am seeking resources that cover the Mathematics of Quantum Mechanics in order to prepare for an exam. The course is not rigorously mathematical, and as such, I am looking for materials comprehensible to the average Physics student. Websites, books, online courses/lecture notes are all...
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    What is the role of zero-momentum frame in two-photon collision processes?

    I don't see how...assuming the expression is true E = \frac{pc}{\beta} = \sqrt{(mc^2)^2 + (pc)^2} I haven't really seen this anywhere. Anyway, are the products moving in the same direction in the galaxy frame? (as neither have any momentum in the zero-momentum frame)
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    What is the role of zero-momentum frame in two-photon collision processes?

    Indeed, its not needed to prove the expression, but the question asked for the two conservation expression in both frames. By β are you referring to v/c? I was thinking of using the "mass shell" formula.
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    What is the role of zero-momentum frame in two-photon collision processes?

    So the identity they want can proved as E_{HE}E_{CMB} = \frac{\Gamma}{\Gamma} E'_{HE}E'_{CMB} = (mc^2)^2 So I have got all the equation except the momentum conservation one in the galaxy frame. I guess the photon momenta can be obtained by p_{HE} = \frac{E_{HE}}{c} But what about the...
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