Charges Definition and 1000 Threads

Homework Statement Griffiths 3.36: Two straight wires having equal and opposite line charges are situated on either side of a conducting cylinder (all the wires and the cylinder are "long", so we can ignore edge effects--this is undergraduate electrostatics, after all!). The cylinder has no...

The charge of an electron is exactly equal in magnitude to that of a proton (2 up quarks plus down quark). What is the theoretical basis for this, or is essentially a fact of nature that is accepted?

Homework Statement why should experiemnts related to static charges be carried out on dry days? Homework Equations I know this somehow relates to the moisture in air. yet, I do not understand the concept behind. The Attempt at a Solution Do the sparks...

1. Two point charges 3.0 cm apart have an electric potential energy -120 microJoules. The total charge is 30 nC. What is the lesser charge? What is the larger charge? 2. Uele=qv Uele=q1(kq/d) 3. My professor gave me these equations, I'm not entirely sure if they're the right ones...

Final distance between two charged, identical particles approaching each other Homework Statement Two identical particles, each with a mass of 4.5 mg and a charge of 30 nC, are moving directly toward each other with equal speeds of 4.0 m/s at an instant when the distance separating the two...

Homework Statement Three point charges, which initially are infinitely far apart, are placed at the corners of an equilateral triangle with sides "b". Two of the point charges are identical and have charge "q". If zero net work is required to place the three charges at the corners of the...

[b]1. Two point charges of equal magnitude are 8.4 cm apart. At the midpoint of the line connecting them, their combined electric field has a magnitude of 45 N/C. Find the magnitude of the charges. [b]2. E=k(q)/r^2 [b]3. I've tried 45= 8.99x10^9(q)/(.084)^2 and got q to equal 35...

A Particle of charge q=7.5x10^-6 Coulombs is released from rest at .6m on the x axis. The particle moves due to charge Q = -20x10-6 C. What is the Kinetic Energy of the particle the instant it has moved .4 meters if Q stays fixed at the origin? Here I used KE1 + U1 = KE2 + U2 Which equals 0 +...

I have some difficulties grasping the idea of this equation W[SIZE="1"]p = q * E * r Where W[SIZE="1"]p - electrical potential energy q - charge E - the strength of the electric field r - radius, or distance from the other point charge So basically, say we have 2 point charges. One...

Homework Statement http://www.screencast.com/users/trinhn812/folders/Jing/media/8fe997e1-46e5-4033-a246-fbad0acb7162 Homework Equations The Attempt at a Solution I understand that in question 25, the conductor becomes polarized and its negative charges will be more attracted...

Homework Statement Calculate how much work it takes to make a square of side length A with point charges (all of charge q) at each vertex. Homework Equations The Attempt at a Solution I know one way to do it. (find the difference in potential for each point and then go from there...

Homework Statement A charge of 0.611 nC is placed at the origin. Another charge of 0.383 nC is placed at x1 = 8.1 cm on the x-axis. At which point on the x-axis does this potential have a minimum? Homework Equations U=(kq1q2)/rThe Attempt at a Solution I really have no idea how to even start...

Attraction between nuclei and electron in QED is the most simply described with Feynman's diagram and calculation, when an electron fastly flow close to a nuclei. (?? scattering) 1. But how, in QED, to describe attraction between almost standstill electron and nuclei. In classical physics...

Hi I'm having difficulty understanding why the solution for the answer to the following problem is worked out this way. Three spheres are placed at fixed points along the x axis, whose positive direction points towards the right. Sphere A is at x=47cm with a charge of 5x10-6C Sphere B is...

A small sphere of mass 1.0 x 10^-6 kg carries a total charfe of 2.0 x 10^-8 C. The sphere hangs from a silk thread between two large parallel conducting plates. The excess charge on each plate is equal in magnitude, but opposite in sign. The thread makes an angle of 30 with the positive...

Homework Statement Attached figure. 3 charges : q1, q2 and q3 are on a plane (for simplification). We want to compute the resulting charge at some point of the plane. 1/ Is it possible to sum (for computation) these charges to an arbitrary point A? 2/ or B? Homework Equations these...

QUESTION 1 Homework Statement Two positive charges, each with Q = +10 µC, are fixed to the x-axis at x = +a and x = -a, where a = 4 m. (a) Find the electric potential at point A on the y-axis where (xA, yA) = (0, b) and b = 5 m. Take the zero of potential to be at infinity. (b) A...

Q1. If two point charges have equal mass and and charg are released on a frictionless table, each has an initial acceleration (Ao). if instead you keep one fixed and release the other one, what will be its initial acceleration?Ao,2Ao or Ao/2? Q2. A point charge of mass (m) and charge (q)...

Homework Statement A point charge of -6 µC is located at x = 1 m, y = -2 m. A second point charge of 12 µC is located at x = 1 m, y = 3 m. (a) Find the magnitude and direction of the electric field at x = -1 m, y = 0. (b) Calculate the magnitude and direction of the force on an...

Homework Statement Grounded conductive spherical shell is given. Radius R. Charge is held in d and (-d). d>R. as in the pic. What is the force on the right charge? Homework Equations F=q*q/r^2 The Attempt at a Solution I thought it's just F=(q^2)/(4d^2). Why it's wrong? the right...

Hi all, Here is my problem: Two positive points charges are situated as the initial figure: 1/ How to compute the voltage between A and B (or C)? 2/ If the final condition is like described in the second figure, what is now the voltage between A and B. 3/ if the transition between the...

A fixed point charge of +2q is connected by strings to point charges of +q and +4q, as shown below. Find the tensions T1 and T2. (Use the following as necessary: q, d and k.) For T1, I summed all the forces on each charge and got...

When using the method of image charges to solve a problem in electrostatics, how do we determine the volume of space in which our solution is valid? And how do we find the solution outside this volume? To be more specific, let's consider two examples. The first is the classic point charge above...

Two charges are located on the y-axis at positions -2 microC @ (0, 2m) and -1 microC (0,-2m). What are the x and y components of the electric field at position (2m,0)?

Consider the arrangement of two fixed point charges, equal in magnitude... Consider the arrangement of two fixed point charges, equal in magnitude, shown in the figure. Which of the following statements are correct for the initial motion of a third charge if it is released from rest in the...

Homework Statement Three charges are at the corners of an equilateral triangle, as shown in the figure below. Calculate the electric field at a point midway between the two charges on the x-axis. Magnitude: Direction below the x-axis in degrees. Homework Equations F=Ke*q/(h)^2...

Homework Statement Three point charges are located at the corners of an equilateral triangle as in the figure below. Find the magnitude and direction of the net electric force on the 0.40 µC charge. (A = 0.20 µC, B = 6.60 µC, and C = -3.80 µC.). Diagram below... Homework Equations F=...

Scene in my book, in the United States. So some guy wants to maybe shoot someone, maybe just scare someone, whatever. But at some point the gun goes off and kills a bystander. Would this be involuntary homicide? Involuntary manslaughter? Any other charges a prosecutor might add? The...

Hi, I saw this article on youtube about Brian Greene describing kaluza-klein and some ideas about tiny curved spatial dimensions: I was wondering...I'm looking for an intuitive (general idea without too much mathematics for starters) explanation as to how kaluza or string...

Homework Statement A point charge +5q is located at the origin, and a point charge –3q is located on the x-axis at D = 0.361 m. At what location on the x-axis will a third charge, q0, experience no net force from the other two charges? Homework Equations F = k * (q1q2/r^2)...

Homework Statement Eight 3.0 μC charges are located at the corners of a unit cube centered about the origin with 1mm edges. How much work does it take to bring a 5.0 μC charge from infinity to the origin? Homework Equations U= k*q1*q2/r The Attempt at a Solution r=...

Homework Statement Three point charges +Q are placed at three corners of a square, and a charge -Q is placed at the fourth corner. If Q = 1.00 milli-coulomb and the side of the square has length 1.00 m, find the magnitude of net force that the positive charges exert on the negative charge...

It is known that on a wire carrying steady current there are surface charges (and hence electric field outside the wire, but let's forget about it). This surface charges play an important role to maintain a uniform electric filed along the whole wire. There are only few geometries for which one...

Homework Statement consider two positive charge+Q at the upper corners of a square. two negative charges-Q are located at the lower corners.assume that each side of the square is S. A) what is the total EPE of the array B)what is the electric field at the center of the square? C) how much...

Homework Statement Two wires shown in figure p19.48 carry currents of 5.00A in opposite directions and are separated by 10cm. Find direction and magnitude of the net mag field. (a) at a point midway between the wires. (b) at point P1 (c) at point P2 Homework Equations B=B1+B2?? B= u0I /...

Homework Statement How much energy is need to place four positive charges, each of magnitude +5.0 mC, at the vertices of a square of side 2.5 cm? Homework Equations E = kQ/r^2 The Attempt at a Solution I'm really not sure if what I did is close to correct, but I got an answer...

Hi... Recently read that neutrinos can be Majorana particles only because they are singlets under the unbroken U(1) electromagnetic.. I can understand that...Majorana means that the particle is its own antiparticle..this can't happen if it is charged, as the antiparticle should have...

Homework Statement There are two of the exact same masses with mass 2.0g and are attached to the ends of an insulating thread that is 0.6m in length. The two spheres are suspended by a hook in the ceiling from the centre of the thread, and the spheres are given identical electric charges and...

Homework Statement I have 2 charges: Q1 = 300 uC located at (1, -1, -3) m Q2 = ?? uC located at (3, -3, -2) m Q1 feels a force from Q2 of F1=(8i - 8j + 4k) N 1. Find Q2 2. Find the expression of the E-Field at (3, -3, -2) m (at Q2) Homework Equations F=(k|Q1*Q2|) / r^2 E=(k|q|)...

Homework Statement A negatively charged particle -q is placed at the center of a uniformly charged ring of radius a having positive charge Q. The particle, confined to move along the x-axis, is moved a small distance x along the axis (x << a) and released. Show that th eparticle oscillates in...

Homework Statement Two charges, one positive and one negative, are separated by a fixed distance. The sign of the potential energy of this pair is always positive; is always negative; is sometimes positive and sometimes negative; depends on the distance. Homework Equations...

Homework Statement The four point charges, each of + 3.00 μC, are situated at the corners of a rectangle of length, b = 60.0 cm and width, a = 30.0 cm. Find the magnitude and direction of the force on q2, due to the other charges. Solved this but i needed someone to check it for me because...

Homework Statement i think i may have solved this but I am worried I am wrong because it seemed too simple. I wouldn't bother posting too check except that its for an assignment... the question is in the attachment- can someone please check this! Homework Equations The Attempt at a...

Homework Statement See attachment--please! Homework Equations F=kq1q2/r^2 The Attempt at a Solution I can't see where to start this question, I can do questions where there is three point charges and it asks you to find the net force on one of them and i think that in essence this...

Homework Statement Two oppositely charged balls are hung by strings from a wooden dowel. The two balls are separated by a distance of R. a) If the balls are moved along the dowel until their separation is 3/2 R, has their potential energy increased or decreased? b) What is the...

Homework Statement Three equal point charges, each with charge 1.95 nanoC , are placed at the vertices of an equilateral triangle whose sides are of length 0.550m . What is the electric potential energy of the system? (Take as zero the potential energy of the three charges when they are...

Homework Statement Two point charges, -30 and +50 , are separated by a distance of 17.0 cm . (micro couloumbs) Express your answer to two significant figures and include the appropriate units. Homework Equations E=kq/r^2 The Attempt at a Solution E1=9E9*30E-6/.085^2= 3.73*10^7...

Why do we take a point charge always while estimating the electric field intensity of a system of charge? as in Coulomb's and Gauss's Law etc.

1. Homework Statement A thin wooden stick of length 12 cm has a tiny metal sphere glued to each end. A charge of +3 microC is placed on one sphere and a charge of -2 microC is placed on the other. The center of mass is located 7 cm from the positively- charged sphere. The system is mounted...

When a charge is given to a metallic sphere it spreads in its entire surface area,and when a charge is given to an insulating sphere, it spreads over its entire volume.Why is it so?