Recent content by cubejunkies

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    Understanding Bias in Semiconductor Devices

    Is there not a difference between bias as in "A diode is forward/reverse biased" and establishing the terminal voltages/currents needed to bring say a transistor to the quiescent point? Just curious
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    Exploring the Pendulum Problem: Energy Loss and Motion in a Vacuum

    Newton's first law states that unless an unbalanced force acts upon a body of matter, causing the mass to accelerate, the mass will stay at rest or travel indefinitely in a straight line with a constant velocity. Pendulums oscillate because gravity and the tension in the pendulum string/cable/...
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    Magnetic Moment Definition Verification/ Proof

    I saw the equation here http://en.wikipedia.org/wiki/Magnetic_moment#Current_loop_definition for the definition of the magnetic moment for a non-planar loop. Can someone tell me if there's a name for this equation m= \frac { I }{ 2 } \int { \overrightarrow { r } } \times d\overrightarrow { r }...
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    2011 AP Physics C E&M frq #1 clarification

    Problem 1 on last year's normal (not form b) frq for e&m part a asked to use Gauss' law to prove essentially that at any point P within a thin spherical shell of charge density σ = q/A and radius r that the electric field at this ambiguous point P is zero. The solutions for this problem went...
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    Derivation of the moment of inertia eqn for a thin spherical shell

    OH WAIT NEVERMIND haha I did some algebraic gymnastics and figured it out :)
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    Derivation of the moment of inertia eqn for a thin spherical shell

    Wait, why does Ro=Ri(1+δ) ? I don't get the (1+δ) part. I also tried expanding as they did on that webpage listed above, using Ro = Ri + r and expanding that, but I can't cancel stuff down like they did and the magical appearance of the factorials in the last step confuses me. Thanks Anthony
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    Derivation of the moment of inertia eqn for a thin spherical shell

    So I've been trying to derive the moment of inertia equation for a thin spherical shell and I've slammed into a dead end algebraically. I was able to derive an equation for a hollow sphere: I = (2/5) M (Ro^5 - Ri^5)/(Ro^3 - Ri^3) where Ro is the distance to the very outside of the sphere...
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    AP Physics C Mech. and E&M self study

    Hey so I'm trying to self study for both AP Physics exams for May 2012, and I've been going through halliday & resnick 7th ed. as a text, however, I feel that this book isn't helping me so much for the mechanics side of things (as I haven't begun to study E&M stuff yet) for two reasons. First...
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    How can I find a copy of John McGehee's unpublished Physics text?

    I've found that syllabus already, and I checked the school website, and I'm fairly certain the McGehee is retired, as my instructor told me that he wrote the workbook when she was still in college, and she is, with all due respect, somewhat older, so I don't think he has an email lying around...
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    How can I find a copy of John McGehee's unpublished Physics text?

    My instructor told me that this unpublished text would aid me greatly in my self-studying for Physics C E&M test, however, since it's unpublished, I have no idea where to find one and my instructor doesn't find one. Any suggestions? Thanks Anthony
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    Help Needed: Solving Physics Problem with Zero Understanding

    My teacher gave us this problem before break in a packet and we basically had to teach ourselves how to do problems like this, and unfortunately, I'm no natural at physics and I might only just have the right equation to apply to the problem yet I have absolutely no understanding of how to use...
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    Can you find the Force without acceleration?

    If the only force acting on the object is the force of gravity, you can use g as the acceleration
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    Can you find the Force without acceleration?

    Draw a free body diagram. What forces are acting on the cannonball as it rolls down the hill?
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    Center of mass x-coordinate of a metal plate

    Thank you so much! I got it right! I tried the problem two other ways before the attempt shown below getting it wrong, but when I finally did: ((10*12*3)-(4*4*pi))/((10*12)-4*pi) which yielded 2.88303, I was right! Thank you so much! :)
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    Center of mass x-coordinate of a metal plate

    Once I do that, what do I do about the circle though? I still am completely lost and don't know what to do :/
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