Recent content by barnsworth

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    What Magnetic Forces Act Between Parallel Current-Carrying Wires?

    1) Four long, straight, parallel wires each carry current I. In plane perpendicular to the wires, the wires are at the corners of a square of side "a". Find the force per unit length on one of the wires if (a) all the currents are in the same direction, and (b) all the currents are in the...
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    Electric Field/Oscillation Problem

    Thanks for the response, f -- but I'm still not quite sure not to do on (d). I did: Coulomb's law: kQq/(1/2L+x)^2 - kQq/(1/2L-x)^2 = kx = ma. a = kQq/m(1/2L+x)^2 - kQq/m(1/2L-x)^2. 2pi*f = sqrt(kQq/m(1/2L+x)^3 - kQq/m(1/2L-x)^3) Which is definitely wrong... I guess it would help if...
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    Electric Field/Oscillation Problem

    A small bead of mass m, carrying a charge q, is constrained to slide along a thin rod of length L. Charges Q are fixed at each end of the rod. a) Obtain an expression for the electric field due to the charges Q as a function of x, where x is the distance from the midpoint of the rod. (Answer...
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    Confusing static equilibrium problem

    static equilibrium problem A 900-N boy sits on top of a ladder of negligible weight that rests on a frictionless floor as in http://m.domaindlx.com/barnsworth/physics.JPG. There is a cross brace halfway up the ladder, and the angle at the apex is 30 degrees. a) What is the force exerted by...
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    Is Your Solution to These Rotational Mechanics Problems Correct?

    Alright here's a problem that seemed pretty easy, but I'm really worried i over-simplified (which i often have a problem of doing) since the question was rated one of the harder ones... 1) A 2000-kg block is lifted at constant speed (v = .08 m/s) by a steel cable pasing over a massless pulley...
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