Charges Definition and 1000 Threads

This isn't a specific question, but more a case of trying to mitigate any potential confusion which might arise in the future. When drawing out curly arrows for mechanisms, and the like, I'm used to thinking about which electrons "belong" to certain atoms (in a book-keeping sense) in order to...

To find ##\sigma_b## I can use a Gaussian surface of a cylinder of length ##L## and radius ##c>r>b##. Since that is inside of the outer conductor, I know the electric field is zero, so I have from Gauss' Law, $$0=2 \pi L\left(b\sigma_b+a\sigma\right)$$ and easily solve for ##\sigma_b##. For...

Current is determined as the amount of charge moving past a certain point of reference (like the point in a wire with current meter clamps around it) in 1 second. This got me thinking , so in a classical resistive load situation with Ohm's law there would be two ways to increase the amount of...

Two charges are moving mutually perpendicular to each other in space with constant velocities. The moment one charge crosses over the line of path of second charge the force on 1st charge (located just behind the 2nd charge moving away from it) appear to be zero (Magnetic field due to 2nd...

Could'nt solve it

I am having trouble solving the following problem. I am given two positive charges on the x axis: I know that the electric field strength at point P is ##E=150 \frac{V}{m}##, ##d=1.8m## and ##a=2.5m##. I want to find the charge of ##Q##. As far as I know, the electric field on the y-axis...

Hi, so I was able to solve this problem by just equating the forces (Tension, mg, and EQ). But I thought I could also solve this problem with Conservation of Energy. However, I calculated it several times, and I never get the right answer this way. Doesn't the Electric Field do the work to put...

Need to set up a spread sheet that shows interest month by month on overdue payments from several unpaid (or underpaid) invoices. I have 13 such invoices, their unpaid amounts, aging in days, and the interest rate. Spread sheet to start from earliest invoice up until 06/14/2019. Thanks!

Consider two opposing mirrors. If they are exactly parallel planes I think there is only a single image in each but if they are slightly angled there appears an "infinite" number of reflections. Similarly, suppose we have grounded conducting planes instead of mirrors with a charge in between...

I am reading the paper of McIrvin: http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.html In fourth picture, two opposite spikes of imaginary magnitude are drawn in momentum space. This is a photon propagator. Photon propagator in p space can be written as...

I have already known the cross sections can be presented like this. σ（e+e- -> hadrons）∝ Σ eq^2 & σ(e+e- -> μ+μ- ) ∝ e^2, where eq is the charge of a certain quark(u, d, s, c or b) But I don't know the relationship between Nc and eq. (This is my first time to post a thread. I don't know how to...

we know that if the applied force is in the direction of the displacement then work done is positive.But in case of bringing 2 opposite charges from infinite to a certain distance,the work done is negative even the force and the displacement of the charge is in the same direction. From...

Summary: Potential at origin of an infinite set of point charges with charge (4^n)q and distance (3^n)a along x-axis where n starts at 1. From V=q/r, we find Vtotal=sum from 1 to infinity of (4/3)^n(q/a), which diverges. There cannot be infinite potential because there is a finite electric...

This problem seems pretty simple but I don't understand how the correct answer is 500,000 smaller than what I calculated. You have an electric field that has a magnitude of 10^6 V/m in the positive z direction. I assumed (though it was not stated) that the cause of this field was a sheet of...

This question is a bit werid because would there be a resulatant electric potential equal to zero as we have a positive and negative charge in which case there's no neutral point. As E1-E2 , they have to be acting in oppostie directions , in this case would they be acting in the same direction.

I have recently started self studying chemistry and I am at the point where I'm learning to name chemicals given chemical formulas and vice versa. (Like Iron (III) Oxide --> Fe2O3). I am having trouble with doing this process for polyatomic ionic compounds. I can't seem to remember some the...

Why is angular momentum conserved for a charge in an electric field?

Let ##(x_1,y_1)## and ##(x_2,y_2)## be the point where the rods intersect the ##x,y## plane. I know that on any given point there will be the superpositions of ##E_1=\frac{2\lambda}{4\pi \epsilon_0}\frac{1}{(x-x_1)^2+(y-y_1)^2}\hat{r}_1## and ##E_2=\frac{2\lambda}{4\pi...

How can a negative charge move towards a position of a higher electric potential from lower potential but lose electric potential energy?From my understanding, I understand that for a positive charge, it must lose potential energy from the electric field as work is done by the electric force in...

Electric field of opposite charges, cancel out each other, is it right?

Homework Statement Homework Equations The Attempt at a Solution I'm sure my solution is wrong because of Φ(z=0) ≠ 0 I searched the internet for a similar problem but I couldn't. Any help will be appreciated.

How does the force between the two opposite charge change if we place a substance (conductor, insulator, ...) between them? It seems that the force between the two charges doesn't change but the total force on each charge increases because of the superposition of the original field of the other...

Homework Statement Three charges q1 q2 and q3 are set along the x-axis. q1 is at the origin and q2 is at r = 11.3mi If q1 = +2.0C, q2 = +1.5C, and q3 = -2.3C, where must q3 be placed so that the net force on it is zero? In other words, the position of q3 is r3 = di, and you must find d...

Homework Statement Homework Equations V=k∑q/r E=-dV/dsThe Attempt at a Solution I found part A plenty fine, 2kq/a From here, I thought that the derivative of -V would give me the electric field, giving -2kq/a^2, but that's not the answer according to what my professor sent. I'm wondering...

Hi. If 2 bodies with charge q are in rest then both have electric force ##F_1=\frac{q*q*k_q}{|\vec{r}|^2}##. But in another frame of reference, that is moving with velocity v relative to first frame of reference, they feel both magnetic and electric force...

Homework Statement Two charges, ##-q_1## and ##q_2## are fixed in the vacuum and separated by a distance ##a##. What should be the velocity ##v## of a particle with mass ##m## and charge ##q##, traveling from an infinitely far point along the line which unites ##q_1## and ##q_2## in order to...

Homework Statement Two conducting spheres A and B, of radii ra and rb, carry charges +Qa and - Qb respectively. The centers of the spheres are a distance d apart with d slightly greater than ra+rb. Which of the following statements about the electrostatic forces F between the spheres is true...

Homework Statement Am amount of charge Q is uniformly spread over a semi-circle of radius R whose center is located a distance A from the origin. What point charge would have to be placed at the origin so that the E field at the center of the circle is 0? (The open end of the semi-circle is...

A charge Q is placed at the centre of the square of side 2.90 cm, at the corners of which four identical charges q = 6.5 C are placed. Find the value of the charge Q so that the whole system is in equilibrium. Can someone help me figure out where I have went wrong, I began by finding the force...

Homework Statement link: https://ibb.co/Xy9s6DR What is the magnitude of this force? Homework Equations Coulomb's Law Trig equations The Attempt at a Solution (.05 m)xcos(60)=0.025m (the distance between the two known charges) F(between the two known...

We know that "plastic" and "glass" charges were arbitrarily assigned to be negative and positive respectively, and electrons and protons were given their charges based upon that assignment (According to Randall D. Knight in Physics for Scientists and Engineers). I am curious if any significant...

Three charges are aligned along a straight wire as show. +C ?<--- -3/2 C --->? -C + q1 -3/2 q3 - q2 X----------------------------o-----------------------------X P(midpoint) |----------------------------...

Homework Statement https://imgur.com/vQRoMjZ Homework EquationsThe Attempt at a Solution I believe that the inductor does negative work on the charges via the electric field (by way of induced EMF). I am unsure about how the capacitor would be doing positive work, though. Can anyone help steer...

So, a static charge at rest produces an electric field, but no magnetic field. A charge moving with constant velocity produces both electric and magnetic fields. Why is it that accelerating charges are the source of all electromagnetic radiation? How would one go about showing this using...

Hello all, after thinking about properties of electromagnetic waves, especially concerning the electric field of them, I ran into some serious understanding problems: 1) photons are electromagnetic waves and vice versa and they convey electrical force. Let's now do a thought experiment: let's...

Homework Statement There is a 3nC charge at (-3,0), -6nC at (0,2) and 5nC at (1,0). What is the electric field at the origin (0,0)? Homework Equations ##E = \frac{Q}{4 \pi \epsilon_0 r^2}## The Attempt at a Solution i think its ##(\frac{1}{4 \pi \epsilon_0})(-\frac{14}{3} i - \frac{3}{2} j)##...

Homework Statement The question askes about the path of the electron. I need to know if I am doing it correctly whether it was asked for a proton or an electron. Homework Equations F=QV⊥Bsinθ The Attempt at a Solution I answered it C. Because it is an electron, I used my left hand. My thumb...

Jim bought a desktop computer and a laptop computer. Before finance charges, the laptop cost \$150 more than the desktop. He paid for the computers using two different financing plans. For the desktop the interest rate was 7% per year, and for the laptop it was 5.5% per year. The total finance...

Homework Statement A particle of charge -q and mass m enterd magnetic field B at A with speed v1 at an angle alpha and leaves the field at C with v2 at angle beta.Then, a)alpha=beta b)v1=v2 c)particle remains in the field for time t=(2m(pi-alpha))/qB d)All of these Please see image below...

Homework Statement Problem attached in Dipole.JpgHomework Equations The Attempt at a Solution I am fine with Part A of the problem. I am just trying to understand what part B is asking. Are they asking what is the magnitude and direction of the dipole vector associated with charges q1 and q1 at...

The reason this is in relativity is ( please correct if wrong )that magnetic fields are effects created by static electricity through length contractions. If a line of electrons move pass a parallel line of positive charges and a charged observer is outside this it would see electrons being...

Homework Statement Homework Equations None (conceptual) The Attempt at a Solution My logic here is this, Sphere 3 has a net positive charge so it is repelling the positives in sphere 2 and attracting the negatives in sphere 2. This means that D has negative charge and C has positive charge...

Homework Statement Consider an infinitely long cylindrical rod with radius a carrying a uniform charge density ##\rho##. The rod is surrounded by a co-axial cylindrical metal-sheet with radius b that is connected to ground. The volume between the sheet and the rod is filled with a dielectric...

Homework Statement A crystal is a periodic lattice of positively and negatively charged ions. (a) Consider an infinite one-dimensional crystal of alternating charges +q and −q, separated by distance d...

Hi I need help to understand how electric potential could be zero at the center of two equal but opposite charges. It seems, there is a no field free region anywhere inside the space between the charges. If I move a test charge from negative to positive charge or otherwise, there seems to be no...

Homework Statement Suppose we have a regular n-gon with identical charges at each vertex. What force would a charge ##Q## at the centre feel? What would the force on the charge ##Q## be if one of the charges at the vertices were removed? [/B]Homework Equations Principle of Superposition, the...

Homework Statement An electric field is created by an uniform linear charge with a linear charge density is 40 nC/m. Find the potential difference between the two points, one of which is situated 5 cm from the line charge and the second at 10cm. Two charges, q and -3q, are situated at a...

Homework Statement Refer the image. Homework Equations kq1q2/r^2 = F Potential energy = kq1q1/r The Attempt at a Solution Obviously since both charges are unequal in magnitude option a is incorrect. Calculating field at large distance r, E = kq1/r^2 - kq2/r^2 = kq2/r^2 Also potential energy...

Homework Statement A point particle of mass m and charge q(>0) approaches to a point particle Q(>0) at a fixed position. When the distance between the two particles is L, the speed of the moving particle is v. The permittivity of the vacuum is denoted as Epsilon0. Find the minimum distance...

Hi all, how much merit does this answer have on Quora? There also an identical answer on Physics Stack Exchange so it'd be nice to confirm or deny the validity of these. Thanks!