Recent content by Gramma2005

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    Double Integrals - Volume vs. Area

    I am confused about when a double integral will give you an area, and when it will give you a volume. Since we are integrating with respect to two variables, wouldn't that always give us an area? Don't we need a third variable in order to find the volume? Thanks for the help.
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    Magnetic Field Help - Physics Problem Solutions

    For Problem 2, just use the equation: r= \frac{m*v}{q*B} except that we just want the velocity perpendicular to the B-field, so we use the equation: r= \frac{m*v*cos(\pi/6)}{q*B} Not sure how to find the pitch though. I'm thinking maybe something like: p = r*tan(pi/6) If you...
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    Finding the Electrical Field from the Electric Potential

    I am trying to solve this problem: The electric potential in a region of space is V = 210x^2 - 270y^2, where x and y are in meters. Find the E-field at (3m, 1m) So I started with: E = \frac{V}{d} so then I plugged x and y into the electric potential equation and got V= -200 Volts...
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    Electrical Potential of a Uniformly Charged Ring

    Alright, I see how it works now, thanks so much for the help. The final solution is: V=\frac{Q*(\sqrt{R_{out}^2+z^2}-\sqrt{R_{in}^2+z^2})}{2*\pi*\epsilon_0*(R_{out}^2-R_{in}^2)}
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    Electrical Potential of a Uniformly Charged Ring

    Would it be something more like this?: V=\frac{2Q}{(R_{out}-R_{in})^2}*\int_{R_{in}}^{R_{out}}\frac{dx}{2*\sqrt{x}} I'm not sure if this is the right integral for the equation?
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    Electrical Potential of a Uniformly Charged Ring

    I am stuck on this problem: I started this problem by looking at the electric potential of a ring, which is: V=\frac{kQ}{\sqrt{R^2+z^2}} So then if it varies in the thickness of the ring, would it be reasonable to have it be: V=\frac{kQ}{\sqrt{(R_{out}-R_{in})^2+z^2}} Or would I...
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    Which Track Will Have the Greater Ball Speed?

    Well, since the tracks both start and end at the same heights, the speed must be the same if they both start at the same speed. Using the potential energy = mgh, and the mechanical energy formula K_f + U_f = K_i + U_i.
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    Suspended in air by adding electrons

    Thanks For The Help That was the right answer. I was just missing the last part, converting it to electrons. Thanks for your help.
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    Suspended in air by adding electrons

    I am stuck on this Physics problem and desperately need some help. As a science project, you've invented an "electron pump" that moves electrons from one object to another. To demonstrate your invention, you bolt a small metal plate to the ceiling, connect the pump between the metal plate and...
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