What is Outside: Definition and 469 Discussions

Homework Statement Find the electric field of a point outside sphere without using Gauss's law. (Do not evaluate the integral) Homework Equations Coulomb's Law Spherical Co-ordinate System The Attempt at a Solution I have attached my attempt as a picture but now I am stuck, I don't know how I...

When one boils a pot of water on the stove, the water starts to boil into steam at 212 degrees Fahrenheit. The stove provides the heat both to make the water 212 degrees, and the stove provides the heat to change the state of the liquid water to vapor. However, we all know that water (or any...

Hi! Could you please help me with the queries below? Thanks a lot. Question 1: My question is about the field outside the plates of parallel plate capacitor. It is said that the field(s) between positively and negatively charged plates gets added up but the field(s) outside the plates gets...

What is the probability of an electron being found outside the atom it belongs to? Is it zero or nonzero?

In the textbook (Introduction to Electrodynamics by Griffiths), the problem in the attached image asks to find the electric field ##E## outside a dielectric. The problem consists of dividing the electric field into the one produced by the negative charges in the dielectric and another by the...

Homework Statement A charged isolated metal sphere of diameter d has a potential V relative to V = 0 at infinity. Calculate the energy density in the electric field near the surface of the sphere. State your answer in terms of the given variables, using ε0 if necessary.Homework Equations Since...

Supposing it were possible to open a stable wormhole close to a planets surface, what could the effects to the immediate area outside the mouth of the wormhole be? Such as radiation, atmospheric anomalies, changes to the planets magnetic field, etc. Thank you for any assistance

Hi, Is it true that the transmission of energy is not inside an electrical conductor, but outside the metal. this even for frequencies around 50 hertz. Thank's

I'm interested in all movies with themes or genres about us being visited by visitors who operate outside the limits of our space-time continuum yet have the ability to cross over into our reality. Try to imagine the guys of Dark City but operating outside time. Have you seen any movies or tv...

if we teleport a small amount of millimeter cube of a neutron star outside it, will it remain still as a very dense heavy neutron clump or will it revert back into its components (iron) or will the neutron destabilize and turn into cosmic radiation of neutrons which then turn back into hydrogen?

Consider Gabriel's Horn, the mathematical object formed by a surface of revolution of the curve x= 1/x from x=1 to infinity. It is known that one can fill the horn with a volume of Pi cubic units of paint but it would take an infinite amount to paint the surface. I think they usually mean the...

Hello, I am looking for an expression to calculate the electrostatic field outside a uniformly charged cylinder, radius R and finite length L. What interests me most is the radial field, E(r) in the plane z = L / 2. I found an expression of the potential V (r) in the case where L <<< R which...

What is the half-life of "novichok" in, and outside, a biological system? There seems to be an "epidemic" of "novichok" poisoning in Great Britain lately, and given that it's a nerve agent, my understanding is that it should be susceptible to fairly rapid decomposition/breakdown.

If I try to calculate the electric field in the x-y plane of a ring of charge resting at the origin on the x-y plane, I keep getting zero. I start with Coulomb's Law. $$ dE(r) = \frac{1}{4\pi\epsilon}\frac{dq}{r^2} = \frac{\lambda R}{4\pi\epsilon}\frac{d\theta}{r^2},$$ in which ##\vec R## is...

If you were to have some way to remove plasma out of a tokamak or stellarator, how would it act? I realize there's basically no way to actually remove plasma from those machines, but I'm curious how plasma would act in the actual atmosphere. Would it act like a plasma cutter? Would it stay...

After thinking a lot about my posts earlier about doing research elsewhere over the summer and discussing things with my professors, I wanted to thank the people here (specifically @Vanadium 50, for being straightforward) for what they said earlier as it made me reflect on my thoughts and...

Yesterday I post a thread, this post is continue of that one. In pic 1 lift is accelerating. A observe inside the lift would assume that he is on planet. if he is on planet time slow on ground and fast in sky. Pic2 shows gravitational field, that have high magnitude in bottom, low at...

Hello everyone :) I have a question.Is it possible for life to exist in other planets without oxygen and water? I mean just because we need it to survive here on Earth.It doesn’t mean all planets need it to support life as well.

Homework Statement An Ohmic material with some conductivity has a uniform current density J initially. Let's say the current is flowing in the direction of the z-axis. A small insulating sphere with radius R is brought inside the material. Find the potential outside the sphere. Homework...

Good day All, I have a confusion in my mind and i hope to clear it If we use the Amper law to calculate the magnetic field outside the cable, the value would be 0 because the electric current inside the amperian loop is equal to 0, but in case we apply the Biot savart law to calculate the...

Homework Statement [/B] A conducting coil of radius R is outside a long solenoid with a cross section of radius r. What is the emf induced in the coil? Most example problems of this type I think are solved based on Faraday’s Law. These examples do not use the distance from the solenoid to the...

Homework Statement A solid sphere with radius R=12 m has charge Q=3 nC distributed uniformly throughout its volume. (a) Calculate the potential difference between a location at infinity and a location on the sphere’s surface. (b) Calculate the potential difference between a location on the...

I was recently having a discussion about magnetic fields outside of a shielded power cable. My understanding up to this point was shielded cables only shields electric fields and not magnetic fields which are associated with current flow inside a cable. For the shielding to shield magnetic...

This is a pretty dumb question, but I honestly just need some advice as to which option to go for. I'm in first year and one of my courses this term is computer science where we will be using matlab. Matlab isn't free- I know that, but my professor said we have two options available for us to...

Homework Statement Homework EquationsThe Attempt at a Solution Option (a), because the potential is 0 on the surface, and potential due to point charge is positive so there must be negative charge on the surface. Since opposite charges attract each other, there is an attractive force...

Homework Statement A current I flows along the surface of a hollow conducting cylinder. The radius of the cylinder section is r. By using Ampere's law, show that the magnetic field B outside the cylinder is B=\frac{\mu_0}{2 \pi} \frac{I}{r} Homework Equations Ampere's law...

I'm interesting in about possibility to express a tetrad of a rotating matter in neutron star (in some approximate known metric, where shape of star is unchanged - Lense-Thirring metric) outside of the equatorial plane. My idea is: I start from Locally Non Rotating Frame (LNRF) in equatorial...

Hi guys. I know that in the US there are the best universities of the world, but I wanted to ask if there are any italian university well-known outside Italy. Without using Google, which are the name of italian universities you know about? Thanks.

Homework Statement An infinitely long cylinder of radius R carries a "frozen-in" magnetization, parallel to the axis, ## \vec M = ks \hat z ##. There are no free currents. Find the magnetic field inside and outside the cylinder by two different methods: (a) Locate all the bound currents and...

Why do charges outside the surface contribute 0 net flux? The book I'm reading says it's because the flux entering the surface cancels out with the flux exiting the surface. But that means E dot Area must be exactly the same magnitude when entering and exiting to cancel out. But we know E-field...

Homework Statement Given 2 positively charged parallel plates with equal surface charge densities, calculate the electric field at a point outside the the parallel plates. Homework Equations E= (surface charge density) / 2(relative permittivity) for a single sheet. The Attempt at a Solution...

I'm confused as to how this expression E= (δ/εo) can't be used to calculate the electric field of a perfectly flat part of a surface even farther from just above the surface.If you just extend the same cylindrical Gaussian surface used for this proof, wouldn't the field stay the same no matter...

Is there any method/model for determining simultaneity of events farther apart than light can ever travel? I'm guessing not. Would it be wrong to say that the non-observable universe exists only in our past (or future)?

Hi everyone. One of the perennial favourite topics here in the Career Guidance section is the employability of physics graduates, including those with just a BSc degree instead of a PhD. I've found the following links on Metafilter and Reddit which I thought might be relevant (the last...

The strong interaction outside nucleons - what mediates it? Is it gluons? Is it mesons? Is it gluons within mesons? Thank you.

Homework Statement Referencing image attached. I'm not sure how the example arrived at ψ ⇒ 0 at x<0 and >L as K ⇒ ∞ in the limiting case of an infinite potential well. Homework EquationsThe Attempt at a Solution I tried simply applying limits to the wavefuction but in the case x<0, the...

I wonder if this question will make sense, but I will do my best shot: As the electron orbits around the nucleus, I imagine there are moments when it is too far away, so it starts to be "pulled toward" the nucleus. If it gets too close, it will be "pushed away". If it is in the orbital area...

Homework Statement A uniform solid sphere of mass M and radius R is fixed at a distance h above a thin infinite sheet of mass density σ. Obtain the magnitude of the force between the sphere and the sheet. Homework EquationsThe Attempt at a Solution I've found the gravitational field from the...

Homework Statement Derive following expression for the electrostatic potential energy of an electron in the field of a finite nucleus of charge, ##+Ze##, and radius, ##R=r_0A^{1/3}##, where ##r_0## is a constant. (Charge density is constant.) The potential we are asked to derive is: $$ V(r) =...

Homework Statement A point charge +Q is placed at the centre of an isolated conducting shell of radius R. Find the electrostatic potential energy stored outside the spherical shell if the shell also contains a charge +Q distributed uniformly over it. Homework Equations [/B] E=kQ/r2...

Homework Statement This is Exercise 19.1 in MTW - See attachment Homework Equations See attachment The Attempt at a Solution [/B] I've worked through 19.3a, 19.3b and 19.3c ( see post by zn5252 back in March 2013 replied to by PeterDonis) and proved them for my my own satisfaction and I've...

This is a simple question but i keep finding conflicting answers and don't understand scientific and mathamatical language well enough to consult reliable data.. 'Cause I'm a dunce. So, is EVERYTHING outside the local group leaving us, or are some things in the virgo supercluster contracting...

Hello. I know you can calculate the magnetic flux density (B) outside a solenoid using Biot-Savart law, but the law uses the magnetic vacuum permeability. Suppose that I placed an iron core in the solenoid, but not outside it. How does B outside change? And now suppose that I place a piece of...

I'm a freshman physics major at a small research university in Philadelphia. The majority of the university is geared toward the health sciences, so we have very limited opportunities for research in physics. I'm just starting to develop my interests in specific fields in physics, and I'd...

Currently I am at the University of Texas at Arlington where I am studying the physical and chemical properties of supernova remnants to figure out the state of its progenitor star. Now, I was thinking of going someplace else to research for the summer, not because I am not interested in the...

Homework Statement In solid state physics,we know all the states of free electrons can be expressed by the First Brillouin Zone. We know the $$E(k+K)=E(k)$$ where K is reciprocal lattice vector. We also know that the kinetic energy of the electron is $$E_{k}=\frac{\hbar^2k^2}{2m}$$. [/B]...

Homework Statement I'm having trouble / uncertainties about the third missing angle (from left to right) in the picture. The first angle of reflection was easy as it's just 34 degrees as well and I used snell's law rearranged to find the first angle of refraction as 13.36 degrees from the...

We're often told that it's helpful to think outside the box. But what is the box we need to think outside of? And what happens when we think inside the box? I've been searching everywhere for the box but I can't find it. Has anybody got it? o0)

Homework Statement A sphere of radius R contains two spherical cavities. Each cavity has a radius of R/2 and touches both the outside surface of the sphere and its center as shown. The mass of a similar sphere without the cavities is M. Find the force of attraction on a small particle of mass m...

Hello, How easy is it to get a job outside the country in which you currently reside? I mean, so far I got responses only from the city where I live regarding my job applications, although I've applied to job positions all over the country. I even haven't gotten any response from any other...