Shell Definition and 784 Threads

Hello I have a conceptual question about the following. Suppose I have a spherical shell with charge density \sigma that is uniformly distributed throughout its surface. My shell has radius a. Then I cut a little circular piece of radius b with b << a. Then I know that my electric field at...

Homework Statement Use the shell method to find the volumes of the solid generated by revolving the regions bounded by the curves and lines. x=2y-y2, x=0 Homework Equations The shell method is of the format: V = 2 \pi\int x * height dx The Attempt at a Solution I cannot...

Hello! I'm new here and I was wondering if anyone could help me. I've a program in fortran which I want to combine with Matlab, both working in Ubunt 7.10 but I don't want to use mex-functions or MATLAB engine functions because it could cause damage to the fortran program I'm using. I was...

A glaucous-winged gull, ascending straight upward at 5.40 m/s , drops a shell when it is 13.5m above the ground. What is the magnitude of the shell's acceleration just after it is released?

Hey all, just a simple question that's confusing me about amplitudes for feynman diagrams. How do i know whether a system needs to be considered as being on shell, and hence has an imaginary component included in the denominator of the propagator? If i have one propagator which is required...

To my understanding this is an electron in the K-Shell being absorbed by the the nucleus and along with a proton converted into a neutron with the emission of a neutrino. My question is what force is acting here? Nuclear? If so, how can nuclear forces act on an electron, when the range of...

What do we mean when we say "on shell" particles? Hello! What do we mean when we say a particle in on shell? What is off shell? I gather it is related to energy and momentum conservation to say if a process is possible, but I've no idea what it actually is. Is it something to do with...

The nuclear shell model is based on the shell model for electrons, and in the electron shell model, lasing is possible under the right conditions. Does this mean that if the nuclear shell model is correct, a nucleus will be able to undergo lasing. And does anyone know if this has ever been...

Homework Statement The inner radius of a spherical shell is 14.6 cm, and the outer radius is 15.2 cm. The shell carries a charge of 5.35 × 10-8 C, distributed uniformly though its volume. Sketch, for your own benefit, the graph of the potential for all values of r (the radial distance from the...

y=x^4, y=sin(pix/2); about x=-1 the solution is attached . how he determinate it to be from 0 to 1 ...? as I know , we usually put for example the expression of y1 = y2 and solve it for zero but in this case is not easy to do it,so how did he do it...?? note: my english is...

Homework Statement Find the electric field and potential inside and outside a hollow spherical shell (a \leq r \leq b) which carries a charge density proportional to the distance from the origin in the region, \rho=kr, for some constant k. Homework Equations The Attempt at a Solution I think...

what the energy spectrum to second order in the field strength for a spherical shell?

I'm trying to write what is basically a search and replace script. Full disclosure: This IS a homework assignment, and my attempt is below. It is supposed to have a usage statement, which I think is pretty solid so far. The problem is at the end where I do that actual searching and replacing...

Hi all, Homework Statement In this question consider the nucleus 15N (The 15 is the atomic mass, so superscript top left of N), and refer to the shell model diagram. (a) Predict the ground state spin and parity, Jpi. (b) Write out the relevant odd particle configuration in the form: p (or n)...

Homework Statement The function is y = 2 - x. The region is bounded by x = 2 and x = 4. Calculate its volume by the shell method by rotating it by the x axis. The Attempt at a Solution This problem has been consuming my mind. I calculated it by the disc method and shell method but I...

Homework Statement 10C of charge are placed on a spherical conducting shell. A -3C point charge is placed at the center of the cavity. The net charge in coulombs on the inner surface of the shell is... A. -7 B. -3 C. 0 D. +3 E. +7 Homework Equations \oint \vec{E}\cdot d\vec{a}...

Homework Statement A cylindrical shell of radius 7.00 cm and length 24.0 cm has its charge uniformly distributed on its curved surface. The magnitude of the electric field at a point 19.0cm radially outward from its axis (measured from the midpoint of the shell) is 36.0 kN/C. Find (a) the...

Homework Statement Consider a solid conducting sphere with a radius 0.7 cm and charge −7.3 pC on it. There is a conducting spherical shell concentric to the sphere. The shell has an inner radius 2.8 cm(with 2.8 cm > 0.7 cm) and outer radius 5 cm and a net charge 27.9 pC on the shell. Denote...

How is it one can hear the sound of the ocean in some sea shells?

Homework Statement A very long insulating cylindrical shell of radius 6.90 cm carries charge of linear density 8.40 microC/m spread uniformly over its outer surface. Find the potential of a point located 4.4cm above the surface of the shellHomework Equations The Attempt at a Solution I used...

Homework Statement Suppose a point dipole is located at the centre of a grounded spherical conducting shell. Find the potential and electric field at points inside the shell. (Hint: Use zonal harmonics that are regular at the origin to satisfy the boundary conditions on the shell.)Homework...

Homework Statement Consider a conducting spherical shell with inner radius 0.8 m and outer radius 1.3 m. There is a net charge 3 μC on the shell. At its center, within the hollow cavity, there is a point charge 3 μC. Determine the flux through the spherical Gaussian surface S, which has a...

This is just a quick conceptual question. If you have a charge on the surface of a conductor, and the gaussian surface within that has a cavity containing a positive charge... and you move that charge off-center, does that affect the charge distribution on the surface of the conductor?

Homework Statement http://img244.imageshack.us/my.php?image=a1physicsmt8.png Homework Equations Gauss' Law The Attempt at a Solution It may be that I'm sick with a cold and can't think straight, but I"m not seeing any way to approach this problem using Gauss' law. I tried using a...

Homework Statement Hey guys. I've been trying to solve this question using Gauss law but I can't think of a surface that can contain this thing. Is there another way to solve this? Thanks a lot. Homework Equations The Attempt at a Solution

Homework Statement Hey guys. I got this question: "Calculate the electric field of half a spherical shell with radius R and uniform surface charge density \sigma along its axis of symmetry above the shell." I guess I shell use Gauss law, the thing is that the Gauss surface will not be...

Homework Statement Three thin (but finite thickness) concentric conducting shells have radii R1 < R2 < R3 and charges -2Q, +Q, and +3Q respectively, where Q is some positive number. What is the charge on the inner surface of the outmost shell? Homework Equations Charge on a conductor...

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Assume that there is a spherical dielectric inside spherical shell. There is a vacuum between the dielectric and the shell. I found this configuration rather tricky. Any idea ? http://img117.imageshack.us/img117/5901/conductorly3.th.jpg...

A nonconducting spherical shell of inner radius a=2.00 cm and outer radius b = 2.40 cm has (withing its thickness) a positive charge density p = A/r, where A is a constant and r is the distance from the center of the shell. In addition, a small ball of charge q=45.0 fC is located at that...

shell model determining spin and parity - urgent Homework Statement Find the spin and parity of _{20}^{41}Ca and _{20}^{40}Ca Homework Equations http://hyperphysics.phy-astr.gsu.edu/hbase/Nuclear/shell.html The Attempt at a Solution For _{20}^{41}Ca we've an odd number...

Express the current density of a spherical shell of radius a, rotating with angular velocity omega, with surface charge density sigma Delta function will be denoted d(x). Spherical coordinates will be used I have concluded that for a given chunk (if we restrict to the 0<theta<pi/2...

In the nuclei Shell Model I understand the nomenclature for the shell sequence but I don’t know how to calculate the respective energy levels for each shell. For example how do you calculate the energy level for 1g(7/2) or 3d(5/2) Pointing me to an online reference will also be...

A 75 kg shell is fired with an initial speed of 125 m/s at an angle 55 degrees above horizontal. Air resistance is negligible. At its highest point, the shell explodes into two fragments, one four times more massive than the other. The heavier fragment lands directly below the point of the...

1. A uniform square plate 7.2 m on a side has had a square piece 3.9 m on a side cut out of it. The center of the missing piece is at x = 1.65 m, y = 0. The center of the square plate is at x = y = 0. What is the x-coordinate of the center-of-mass of the remaining piece? 2...

i'm confused right now about this, when would it be appropriate to use the shell method rather than using the washer or disk method when it comes to looking for the volume of a rotating object?

A shell is shot with initial velocity \vec{}v_{0} is 20ms^{-1} at an angle \vartheta = 60 degrees. At the top of the trajectory, the shell explodes into two fragments of equal mass. Fragment1 has a speed of 0 immediately after the explosion and falls vertically. How far from the gun does...

1. A thin spherical shell of radius a has a total charge Q distributed uniformly over its surface. Find the electric field at points outside the shell and inside the shell 2. \intE dA = Q/\epsilon 3. THis is an example in my textbook, and it claims that: The calculation for...

Hi there , I'm a bit rusty on the subject so I have 2 questions , although they are quite similar. Anyways first one : Lets say i have a sphere charged with Q , and around that sphere I have a conductive shell (also a shpere) at some distance from our charged sphere . The conductive shell...

1. A thick conducting cylindrical shell has an inner radius Rsub1 and outer radius Rsub2. It has a net excess charge = Q, and it is L long. Find electric field at certain points given. Ok, when r is less than Rsub 1, the electric field is zero. And when r is greater than Rsub2, it is easy to...

My knowledge of chemistry is almost nil - but anyways, I was wondering - what happens when two electrons in the same shell collide? From what I understand is that electrons do not travel in a perfect orbit and randomly wobble a bit. If this is true, then isn't it possible that one electron [in...

Homework Statement Electric Charge is distributed over a thin spherical shell with a density which varies in proportion to the value of a single function P_l(cos \theta) at any point on the shell. Show, by using the expansions (2.26) and (2.27) and the orthongonality relations for the...

A grounded & conducting spherical shell of outer radius M and inner radius N has a point charge Q inside the shell at a distance r<M from center. Using method of images, find the potential inside the sphere. Could I just use the superposition of charge and point charge? \phi(r) =...

[solved] Potential inside (and outside) a charged spherical shell Homework Statement Use the integral (i) to determine the potential V(x) both inside and outside a uniformly charge spherical surface, with total charge Q and radius R. Homework Equations (i) V(\vec{x}) =...

In Weinberg's book, he said "Feynman graphs with lines off the mass shell are just a special case of a wider generalization of the Feynman rules that takes into account the effects of various possible external fields." Suppose the external fields are treated as a c-number, \epsilon_a(x), and...

A long non-conducting cylinder has a charge density p = a*r, where a = 4.73 C/m^4 and r is in meters, and a radius of 0.0437m . Concentric around it is a hollow metallic cylindrical shell with an inner radius of 0.119m and an outer radius of 0.158m. 1) What is the electric field at 0.172m...

Can someone explain to me when you should user the Shell / Disk / Washer methods? I don't understand how to determine which method to use.

Follow the below four steps to amuse yourself 1) Take a semicircular wire. You know that its COM is at (0,2R/\pi). Now pass an axis through its COM and perpendicular to the line joining its ends. 2)Rotate this "half-lollipop" about the axis fixed till it comes to another position. The COM...

hey, i have a question from an exam paper which isn't worded too nicely (most of the questions on the exam are worded in similar ways ) The way I've done it is to first put in my first shell of infintesimal charge and then treat it as a point charge. Then i treat the next shell as just a point...

How do I solve for the temperature at a certain time for conduction through a spherical shell? I have a shell 5 cm thick with a radius of 0.5m. I am starting with Q=KA(T2-T1)/L and I am completely lost as to where to go with it. Thanks!