Shell Definition and 784 Threads

Let's consider two spherical blackbodies at two foci inside an ellipsoidal heat-reflecting shell. Consider the situation that they both have different radii and that their temperatures are such that they emit the same power. Thus, the surface power flux density of each is inversely proportional...

Homework Statement A positive point charge q is located off-center inside a conducting spherical shell.We know from Gauss’s law that the total charge on the inner surface of the shell is −q. Is the surface charge density negative over the entire inner surface? Or can it be positive on the far...

Homework Statement Find the force that tries to rip apart a conducting shell into two halves about its equator when kept in a uniform electric field of magnitude ##E##. Homework Equations Gauss Law: $$\nabla\cdot\vec{E}=\frac{\rho}{\epsilon_0}$$ I think Laplace equation might also be...

Homework Statement A metal sphere of charge +6μC is surrounded by a metal shell of net charge +6μC. Which of the following diagrams represents the electric field lines of the system? Homework EquationsThe Attempt at a Solution The correct answer provided by my teacher is a figure with 12...

I'm a bit confused about how things fill up in the shell model. Here is my understanding: the potential we are working with is the net potential due to the other nucleons that a proton or neutron feels throughout the nucleus; it is a combination of a square and harmonic oscillator potential...

The reason I ask is because by definition entangled particles, like electrons, are always precisely the opposite spin of each other. At the same time it's known that for electrons to share an electronic shell with another electron, that they too must be precisely the opposite spin of each other...

When a bubble in liquid expands or contracts it can be seen as having a liquid shell that gets larger on expansion and smaller on compression. The idea of diffusion is what I am struggling with, if the bubble was getting bigger and the liquid shell contracts then surely it would become more...

Homework Statement A) [/B]Consider a hollow sphere of uniform density with an outer radius R and inner radius \alpha R, where 0\leq\alpha\leq1. Calculate its moment of inertia. B) Take the limit as \lim_{\alpha\to1} to determine the moment of inertia of a thin spherical shell. Homework...

I am considering the following one loop virtual correction in the DIS process. where I have a quark of momentum ##p## coming in, emitting a gluon before interacting with a photon of momentum ##q## to produce a fermionic propagator with momentum ##p+q##. My question is, in the red box, I...

Homework Statement Find the volume of the solid obtained by rotating y=x^2 and x = y^2 about y=2 Homework Equations V= 2πrh The Attempt at a Solution When I had constructed the graph I determined the following: r= 2-(y(1/2)) h= 1-y2 after converting V into an integral I applied fundamental...

I've read the postulate that there could be a huge spherical dark matter halo extending far beyond the edges of the Milky Way. However, according to Newton's shell theorem, there is no net gravitational pull within a shell. How do they arrive at the conclusion of a halo so huge?

1. Calculate the work that must be done on charges brought from infinity to charge a spherical shell of radius R = 0.100 m to a total charge of Q = 125 μC.2. V = k_e\int{\frac{dq}{r}} \triangle V = - \int{E \cdot ds} W = q\triangle V 3. I started with assuming the spherical shell produces an...

Homework Statement A nonconducting thin spherical shell of radius 6.80 cm has a uniform surface charge density of 9.28 nC/m2. i) What is the total charge on the shell? ii) Find the electric field at r = 2.43 cm. iii) Find the electric field at r = 6.61 cm. iv) Find the electric field at...

If you raise the electron to other higher shell states, can light transmission throug -h a SOLID BLACK opaque object. Modified the original question because it was unclear. I won't repeat the same question over, and over, but what I have said in previous questions may get repeated in the...

Is there a general way of knowing if an elementary boson for example is virtual or real? So for example, two leptons annihilate into an elementary boson. Then you can get real photons, W+-/Z° bosons depending on the leptons. However W+-/Z° and photons can also be virtual when acting as...

Homework Statement The metal with the electron shell configuration of [Ar] 3d10 s1 is A. Cu B. Ag C. Au D. Zn E. Al Homework Equations -[/B] The Attempt at a Solution I don't really know how because shouldn't the s shell be filled before the d shell in period 4? Thanks!

Homework Statement A metallic sphere is placed inside a hollow spherical shell. The potential on the inner and outer spheres is 10 V and 5 V respectively. What is the potential at the center?(The spheres are concentric.) Homework Equations $$V =\frac{kq}{r}$$ The Attempt at a Solution The...

Dear PF Forum, I think I have asked too many question for one day. I'm trying to understand antioxidant and free radicals. But, first I'd like to understand oxidation number. The oxidation number for hydrogen is +1 or -1. I can understand that. Either Hydrogen must lost one electron or gains one...

Let's say we have a plasma of protons or deuterons and electrons; how thick is the 'shell' that the nuclei form in momentum space compared to the 'shell' formed by D2 or H2 in a gas, at room temperature? Will the distribution of momentum be more spread out or more compact, so to speak, in a...

Homework Statement There are three point charges inside a conducting spherical shell of radius R. One of them of charge -2q is in the origin and the other two with charge q are in z=d and z=-d. Find the potential inside the sphere! Homework Equations ##\nabla^2\phi=4\pi \rho## 3. The attempt...

Hello all, Guys in my textbook they state that on a point mass at point outside spherical shell of uniform density, the gravitational force is just as if the entire mass of the shell is concentrated at the Centre of shell. The text also states, the force of attraction due to a hollow...

An unfortunate incident happened at our triple effect caustic evaporator (32w.t% to 51w.t%). The third effect (highlighted red) where major steam (~12-13bar depending on flowrate) assisted evaporation take place, here for some reason Ni tubes get severely collapsed, while the plant was offline...

Edit: Forgot to type "stumped" at the end of the title 1. Homework Statement Instead of typing it out, a link to a scanned document of the problem is here: http://imgur.com/Be3jSLp. Homework Equations The equations to use are stated in the problem here: http://imgur.com/Be3jSLp The Attempt...

Hello, I would like to thank all of the contributors on this site. You have helped me in more ways than I can count. I am struggling with the following concept and was wondering if anyone could clarify this. As the electron gets further away from the nucleus, its energy increases. This makes...

I've just watched half a dozen or so videos on shell theorem and I just can't get my head around something that none of the videos address directly, but seems so counter-intuitive I am assuming my understanding is incorrect. Can anyone help me out here? With all the usual simplifying conditions...

Figure (a)shows two concentric conducting shells .Some charge Q1 is given to the outer shell.No charge is developed on the inner shell.I want to know why?When charge is on inner sphere ,charges also develop on outer shell then why not charge develops on inner shell when there are charges on...

Homework Statement [/B] A shell of mass m and speed v explodes into two identical fragments. If the shell was moving horizontally (the positive x direction) with respect to Earth, and one of the fragments is subsequently moving vertically with speed v, find the velocity v of the other fragment...

So I'm getting ready for an exam on tuesday, and I'm using each method for volumes of revolutions for every problem but I'm not getting the same answers. So, let's use this as an example: y = 5x; the shaded region is from [1,2] Using the disk method (about the x-axis) I find: R(x) = 5x; r(x)...

Homework Statement Find Electric field at center of charged hemispherical shell Homework Equations In spherical coordinates, $$dA=R^2\sin\phi d\phi d\theta$$ The Attempt at a Solution From the image, Enet=2dEy=2dEcosφ $$dE=\frac{kdq}{R^2}E$$ $$dE=\frac{k\sigma dA}{R^2}$$ $$dE=\frac{k\sigma...

A gun of mass M fires a shell of mass m and recoils horizontally. If the shell travels with speed v relative to the barrel, find the speed with which the barrel begins to recoil if (a) the barrel is horizontal (b) the barrel is inclined at an angle A to the horizontal.

Here's the question I am thinking about: If there is a spherical shell with uniform charge on it, I know the electric field inside the shell is zero and that outside the shell is calculated just the same with a single charge at the center of the sphere, but how about the field just at the shell...

Homework Statement Find the moment of inertia of a spherical shell (hollow) with mass M and radius R. Homework Equations ## I = \int r^2 dm ## The Attempt at a Solution This is method I use to find Moment of Inertia of solid sphere: We use circular cross sections. At some radius r...

In my physics lab, I am asked to calculate the volume of a hollow cylinder. The equation for the volume hollow cylinder below was given. Then, my curiosity made me wonder, is the volume of the hollow cylinder the same as the volume of a cylindrical shell used in calculus? At first though you...

I've put the problem statement below and worked it out. I typically don't post questions like this as they're a lot to go through, but I am wondering if I have worked the problem correctly as my book does not have the solution and I feel like I am not understand the material correctly. 1...

Homework Statement Ok.Then there was a question If r is distance measured from center of a charged shell and R is it's radius then the graph which may correctly represent variations of electric field is Homework Equations E vs R graph The Attempt at a Solution The answer is given to be A...

I want to ask Is conducting shell same as uniformly charged thin spherical shell? Because while finding Electric field due to uniformly charged thin spherical shell surface charge density is taken the same happens in case of conducting/metallic shell all the charges reside on surface similarly...

Consider a pressurized cylindrical shell of radius r and pressure p, which at equilibrium has a nonvanishing in-plane stress components pr/2 and pr. This result is generically found by force-balancing. However, if I bent a pressurized torus into this cylinder, then the pressure will still give...

Homework Statement Suppose a hollow metal shell (outer radius 25.3 cm, inner radius 5.2 cm) carries charge Q = -7.99 pC. There is a tiny hole in the sphere, so small that it does not affect the charge distribution or the electric field created by the charge. An proton is released from rest at...

Homework Statement A point charge q is at the center of an uncharged spherical conducting shell, of inner radius a and outer radius b. How much work would it take to move the point charge out to infinity (through a tiny hole drilled in the shell)? [answer: q2/8πε0)(1/a - 1/b) Homework...

The problems states: An inverted hemispherical bowl of radius R carries a uniform surface charge density σ. Find the potential difference between the north pole and the center. I was able to do the problem and got the correct answer the book gives, which is (Rσ/2ε0)(√2 - 1). My professor...

Figure (a) shows a narrow charged solid cylinder that is coaxial with a larger charged cylindrical shell. Both are nonconducting and thin and have uniform surface charge densities on their outer surfaces. Figure (b) gives the radial component E of the electric field versus radial distance r from...

Hello, PF! I have some doubts about setting up shell balances in a cylindrical geometry. Consider a fluid flowing down a vertical pipe. In order to perform the momentum balance, we take a cylindrical (annular) shell of length L and width Δr. The analysis of such system can be found in chapter 2...

Homework Statement Given a spherical shell of radius R and the surface charge density ( being the angle from the top of the sphere and being a constant) find the electric potential and the electric field inside and outside the sphere. Check that both the potential is continuous inside and...

Homework Statement A charged spherical insulating shell has inner radius a and outer radius b. The charge density on the shell is ρ. What is the magnitude of the E-field at a distance r away from the center of the shell where r < a? Homework Equations Gauss' Law The Attempt at a Solution I...

Homework Statement An infinite line of charge with linear density λ1 = 6.9μ C/m is positioned along the axis of a thick insulating shell of inner radius a = 2.6 cm and outer radius b = 4.8 cm. The insulating shell is uniformly charged with a volume density of ρ = -656μ C/m3 1)What is λ2, the...

Homework Statement A hollow spherical shell (B) with inner radius R2 and esternal radius R3 is negatively charged with Q. A spherical conducter (A) with radius R1 is placed within the the shell. A is charged with Q. The centers of both shells coincide. Then a negative point charge q is placed...

I have worked through proofs of the Shell Theorem using the integral form of Gauss's Law. However, in this exercise (I'm self studying) we have not covered the integral form of Gauss's Law, so we're looking for an alternative proof. What we have is the definition of divergence and Gauss's law...

consider two concentric spheres, where inner radius is r and outer radius is r+delta. Assume space between the two spheres is mass of an amount to be solved for. Given the metric inside the sphere, assumed to be varying as implied by the Cosmic Background Radiation anisotropy (CBRa), can the...

Homework Statement This is the main question.So I'm stuck at the b part It says that the shell radius is (3)^1/2 - (3-y^2)^1/2 but i would only say (3-y^2)^1/2.Why do we say otherwise? Homework EquationsThe Attempt at a Solution i would say the shell radius is (3-y^2)^1/2 but it's wrong

Homework Statement Consider a non-conducting sphere of radius 'R' and charge 'Q' is enclosed by spherical shell of radius '5R' and charge '4Q'. If inner sphere is expanded to radius '3R'.Then amount of work done by the field in this process is Homework Equations W=ε0/2∫E2dτ The Attempt at a...