Recent content by Froskoy

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    Geometrical optics - lens floating in mercury

    Homework Statement Consider a thin bi-convex lens with refractive index n which has spherical surfaces with equal radii of curvature r and a measured focal length f. The lens floats horizontally on the surface of liquid mercury so that its lower surface effectively becomes a spherical mirror...
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    Impulse of a force - effect on linear and angular momentum

    Thanks very much! It all makes a lot more sense now!
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    Impulse of a force - effect on linear and angular momentum

    Hi, I'm having trouble understanding what the relation is between the impulse of a force during a collision and the changes in linear and angular momentum during the collision. I know that the principle of conservation of linear momentum says that the total linear momentum before is equal...
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    Vector calculus question - surface of ellipsoid

    Homework Statement Let E be the ellipsoid \frac{x^2}{a^2}+\frac{y^2}{b^2}+z^2=1 where a>\sqrt{2} and b>\sqrt{2}. Let S be the part of the surface of E defined by 0\le x\le1, 0\le y\le1, z>0 and let \mathbf{F} be the vector field defined by \mathbf{F}=(-y,x,0). Given that the surface area...
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    E-P invariant on relativistic mecahnics problem

    Homework Statement A particle of mass m moving at speed \frac{3}{5}c collides with an identical particle at rest, and forms a new particle of mass M which moves off at speed v. Find v.Homework Equations E-P invariant: E_1^2-p_1c^2=E_2^2-p_2^2c^2=\mathrm{const.} Momentum...
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    Fundamental theory of calculus

    Homework Statement The question: The function F(θ,k) is defined as F(\theta,k)=\int_0^θ (f(x,k))\mathrm{d}x Find expressions for \left({\frac{\partial F}{\partial \theta}}\right)_k and \left({\frac{\partial F}{\partial k}}\right)_θ Homework Equations Fundamental theory of calculus Chain...
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    Taylor expansion - imaginary coefficients?

    Thanks! I hadn't thought of expanding \frac{1}{\sqrt{x^2-a^2}} and then multiplying my x - that's really cool - thanks!
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    Taylor expansion - imaginary coefficients?

    Homework Statement Find the first two non-zero terms in the Taylor expansion of \frac{x}{\sqrt{x^2-a^2}} where a is a real constantHomework Equations f(x)=f(x_0)+f^{\prime}(x_0)(x-x_0)+\frac{f^{\prime\prime}(x_0)}{2!}(x-x_0)^2+...+\frac{f^{(n)}(x_0)}{n!}(x-x_0)^n The Attempt at a Solution If...
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    Position of particle in infinite potential well

    Why? Please can you point me to somewhere that explains how this situation is modeled classically?
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    Phase of current and voltage in LCR network

    Thank you so much! It's all really clear now!
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    Position of particle in infinite potential well

    Homework Statement For the case n=1, calculate the probability that the particle is found in within the region a/4<x<3a/4 (n is the energy level, a is the width of the infinite potential well). Compare this result with the case n=8 and with the classical result. Homework Equations...
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    Phase of current and voltage in LCR network

    Homework Statement A network consists of an inductor, capacitor and resistor are connected in parallel and an alternating sinusoidal voltage is placed across the network. Sketch the phase of the total current relative to the voltage as a function of the angular frequency. The Attempt at a...
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    Second order differential equation using substitution

    Thanks very much! Have got it now!
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    Second order differential equation using substitution

    Homework Statement \sin\theta\frac{d^2y}{d\theta^2}-\cos\theta\frac{dy}{d\theta}+2y\sin^3\theta=0Homework Equations Use the substitution x=\cos\thetaThe Attempt at a Solution I started off by listing: x=\cos\theta\\ \frac{dx}{d\theta}=-\sin\theta\\ \frac{d^2x}{d\theta^2}=-\cos\theta\\ But...
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    Magnitude of a velocity vector with special relativity

    Hi, I'm trying to get my head around how velocity vectors work in special relativity. For example, in classical mechanics, the magnitude of the velocity would be given by: v^2 = \sqrt{v_x^2 + v_y^2 + v_z^2} where v_x, v_y and v_z are the x, y and z components of the velocity...
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