Recent content by valarking

ah, i see. redoing the integral simply gives an answer with rho*l in the numerator rather than rho*l^2 thanks

How do you figure I got Ohm*m? The numerator of the fraction has Ohm*m^2 The denominator has m^2 And the units of the logarithm's contents cancel out edit: Oh, I think you're looking at my answer in the original post. That one's definitely wrong.

It's not online so I won't know until I turn it in. Thanks for all the help.

well take for example, if a and b were 4 and 6, and l was 8 at x = 0, we get 4h at x = 8, we get 6h the way i have it set up, it's simply an integral that assumes the x-axis is along l and integrates along that.

Here's my attempt along your suggestions: A = h\left(\frac{(b-a)x}{l}+a\right) So I'm looking at: R = \int_0^l{\frac{\rho{l}}{h\left(\frac{(b-a)x}{l}+a\right)}dx} This eventually works down (after some lengthy calculus) to: \frac{\rho{l^2}}{h(b-a)}ln\left(\frac{b}{a}\right)

Somewhat. I think you may be looking at the cross sections slightly differently, as you mention the constant width, but it looks like length and height are constant, and the only thing that changes is the width (from a to b). I see what you are saying about using dl for the integral, so I will...

Homework Statement http://www.vkgfx.com/physics/p5.gif Homework Equations R = rho*l/A The Attempt at a Solution Initially I thought this would be easy. I could just write the surface area A of the trapezoid by its geometric area formula and multiply it by h. I thought about it though...

Ok, I see what you're saying, and that sounds right. Thanks again for the help.

I thought that both capacitors were used in RC, the time constant, and that C1 was used by itself only when dealing with Qf, or C*epsilon. Basically, I was fairly certain that the time constant is the same regardless of which capacitor you are looking at. Is this not the case?

Ok, that would give: {C_1}\epsilon(1 - e^{\frac{-t}{(R_1+R_2+R_3+R_4)(C_1+C_2)}})e^{\frac{-t}{(R_3+R_4)(C_1+C_2)}} as the answer then. Thanks for your help.

So would the time constant for the discharging period be (R3+R4)(C1+C2)?

Homework Statement All capacitors of the open circuit in fig. 3 are discharged when, at time t=0, the switch S1 is closed. At some point later, at time t = t1, the switchS2 is also closed. What is the charge Q1(t2) on the capacitor C1 at time t = t2 > t1? http://www.vkgfx.com/misc/fig3.jpg...

Homework Statement We have a hollow insulating spherical shell of inner radius a and outer radius b. While it can be treated as a point for r > b, find the electric potential on the inner surface of the shell. Homework Equations \phi = k_e\frac{q}{r} The Attempt at a Solution My...

Homework Statement Three conducting spheres of radii a, b and c, respectively, are connected by negligibly thin conducting wires as shown in figure 4. Distances between spheres are much larger than their sizes. The electric field on the surface of the sphere of radius a is measured to be...