Charges Definition and 1000 Threads

(solved) Finding charges in a pendulum in equilibrium Homework Statement Two small metallic spheres, each of mass 0.20 g, are suspended as pendulums by light strings from a common point. The spheres are given the same electric charge, and it is found that the two come to equilibrium when...

In ch 30-7 of the Lectures, Feynman explains that the field of a plane of oscillating charges at a point P is proportional to the velocity of the charges, considered at the appropriate retarded time (retarded by the vertical distance from the point P). Feynman derives this formula only for...

Homework Statement Hi guys! If I have two positive charges really close to each other, what would be the electric stress between the positive charges? Now I don't need a numerical answer, but I would like to know if my attempt is correct. Homework Equations σ=ε(EiEj-(1/2)δij(E^2))...

Two charges q1 = 3.0µC and q2 = −4.0µC initially are separated by a distance ro = 2cm. An external agent moves the charges until they are rf = 5cm apart. a) How much work is done by the electric field moving the charged from ro to rf? Is it negative or positive? What is the work done by a...

My teacher's notes don't explain this. What are free and bound charges, and why are the H and D field defined like they are?

Homework Statement Two point charges (opposite signs, equal in magnitude) are a distance d apart. Point P is a distance z above both charges and horizontally equidistant. Find the electric potential at point P. Homework Equations Kq/r The Attempt at a Solution It's my...

Homework Statement Consider the arrangement of two point charges equal in magnitude but opposite sign (+Q, and -Q), which are a fixed distance d apart. Can you find a location where a third positive charge Q could be placed so that the net electric force on this charge is zero? Homework...

Homework Statement Two small beads having positive charges 3q and q are fixed at opposite ends of a horizontal insulating rod, extending from the origin to the point x=d. A third small charged bead is free to slide on the rod. At what point is the third bead in equilibrium? Explain whether it...

Homework Statement Find the magnitude and direction at the midpoint of two point charges q1=20nC and q2=-40nC Homework Equations How can we answer the question if we aren't given the distance? The Attempt at a Solution Do I solve in terms of x for distance and use the formula...

Homework Statement "A point charge of 3*10^-6 C is at the origin and another point charge of -4*10^06 C is at point 0.1m away along the x axis. What is the magnitude and direction of the electric field at point 0.15m from the origin along the posting y-axis? Homework Equations E=...

Homework Statement Two point charges are located on the y-axis as follows: charge q1=-2.5nC at y=-0.6m, and charge q2=+3.5nC at the origin. What is the net force (x, y components) exerted by these two charges on a third charge q3=+5.0nC located at y=-0.4m? Homework Equations F=k...

Homework Statement Consider an originally neutral conductor sphere of radius R with a cavity and a point charge Q1 inside the cavity. (a)The conductor is grounded. Find the electric potential outside the conductor and the total charge on the conductor. Homework Equations The Attempt at a...

We all know the coulomb's law of electrical force between two charges q_1,q_2 equals to \normalsize F= Kq_1q_2/d^2. But this law is not precisely true when the two charges are moving. We know for a single charge q moving with a velocity v the force is \ F=q(E+v×B) What is the straightforward...

Homework Statement Compare the electrostatic energy of two opposite charges e and -e, a distance 7 angstroms apart in water at room temperature and that in vacuum (express the energy in terms of Bjerrum length) Homework Equations E = 1/(4(p\pi\epsilonD)*(-e^2)/r^2 ? The Attempt at a...

Homework Statement Four positive charges are located on the corners of a square of side-length a. The charges are A=4, B=2, C=8 4q----a----q |------------| a-----------a |------------| 2q----a----8q Determine the magnitude and direction of the electric field experienced by charge q in terms of...

my question is , what's the fundamental difference difference between positive and negative charge? i mean in what way a positron and a electron are fundamentally different? is it spin properties or others?

Homework Statement A small metal sphere, carrying a net charge of q1 = -2.90 μC , is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q2 = -7.20 μC and mass 1.70g , is projected toward q1. When the two spheres are 0.800 m apart, q2 is...

Why don't magnetic fields not force to charges/currents that are moving parallel to the field? Does it have something to do with the orientation of the field created by the moving charge in relation to the field it is in? I know the answer of this question may not be clear yet, but are...

Why do magnetic fields only apply force to charges/currents that are perpendicular to the field? Does it have something to do with the orientation of the field created by the moving charge in relation to the field it is in?

Homework Statement Point charge 2.5 microC is located at x = 0, y = 0.30 m, point charge -2.5 microC is located at x = 0 y = -0.30 m. What are (a)the magnitude and (b)direction of the total electric force that these charges exert on a third point charge Q = 4.5 microC at x = 0.40 m, y = 0...

Homework Statement Two balls, one with charge Q1 = +Q and the other with charge Q2 = +2Q, are held fixed at a separation d = 3R as shown. See picture. Another ball with (non-zero) charge Q3 is introduced in between Q1 and Q2 at a distance = R from Q1. See right below first...

Homework Statement 5. There are two charges in space. In which region of the line connecting these two charges can we find a point of zero electric field? Homework Equations None. The Attempt at a Solution I know this isn't even that hard. I was thinking it was somewhere in...

Imagine you have a regular 13 sided polygon with charges distributed on every corner of the polygon. What would a test charge experience in the center? The answer to that was a 0 net force (which makes some intuitive sense to me due to the symmetry of the polygon). I understand that if we...

1. Three charges are at the corners of an isosceles triangle as shown in the figure. The +q1 = 5.05 uC and -q1 = 5.05 uC charges form a dipole. A) Find the magnitude and direction of the net force that the q2 = 8.50 uc charge exerts on the diple. B) For an axis perpendicular to the line...

Hello friends, I recently, was reading all about the accelerating charges and radiation, but somehow the classical electrodynamics treatment is still inadequate, that is, the radiation reaction force(derived for oscillating charges) vanishes for uniformly accelerating charges. In this view...

Homework Statement Current passes through a solution of sodium chloride. In 1.00 second, 2.68*10^16 Na+ ions arrive at the negative electrode and 3.92*10^16 Cl- ions arrive at the positive electrode. What is the current passing between the electrodes? Final answer must be in milliamperes...

Homework Statement In the figure below, six charged particles surround particle 7 at radial distances of either d = 1.0 cm or 2d, as drawn. The charges are q1 = +8e, q2 = +8e, q3 = +e, q4 = +8e, q5 = +8e, q6 = +4e, q7 = +4e, with e = 1.60 10-19 C. What is the magnitude of the net electrostatic...

Homework Statement Determine the magnitude of the force between two point charges, Q1 = -2e located at (-3.60 cm, +4.10 cm) and Q2 = -8e located at (-0.60 cm, -8.60 cm). Give your answer in the form "a.bc x 10^(y) N". Homework Equations F = kq1q2/r2 The Attempt at a...

Homework Statement Two identical + 8.5mu C point charges are initially 2.5 cm from each other. If they are released at the same instant from rest, how fast will each be moving when they are very far away from each other? Assume they have identical masses of 2.0mg . Homework Equations...

Homework Statement Three point charges are arranged on a line. Charge q3 = +5.00nC and is at the origin. Charge q2 = -4.00nC and is at x = 4.50cm . Charge q1 is at x = 2.00cm. What is q1 (magnitude and sign) if the net force on q3 is zero? Homework Equations The Attempt at a...

http://imgur.com/a3vxU Really haven't a clue how to go about this, it's the last question on the paper and nothing before it is anything near as complex as this. Any help much appreciated

Homework Statement Two infinite line charges, of charge density λ Cm-1, are aligned parallel to one another as shown in the diagram below. The line charges are a distance 2a apart. An electron is placed at location (x, 0, 0), x << a and released. Show that it will execute simple harmonic...

Homework Statement See attachment Homework Equations The Attempt at a Solution I was successful with finding a solution. But, only because I tried the practice version of that (where you can see the answers) and noticed the equation I derived gave angles that, when summed with...

Curious what people's opinions are on this. Does anyone have a link to the investigation and evidence. http://www.reuters.com/article/2012/08/24/us-cycling-armstrong-doping-idUSBRE87N03N20120824

Homework Statement Two identical conducting spheres, fixed in place, attract each other with a force of 0.111 N when their center to center separation is 45.00 cm. The spheres are then connected by a thin conducting wire. When the wire is removed, the spheres have a net positive charge and...

Homework Statement Four point charges, two of charge +q and two of charge -q, are placed in an arbitrary way. Each charge is located a distance r_i < R from the origin. Find the electric field at r >= R. Homework Equations According to Gauss's law, the field should be zero, right...

Let's suppose, we have two ideal point charges q_{1}, m_{1} and q_{2}, m_{2}. One of them comes from almost infinite distance with relative velocity v_{0}, w.r.t another charge. I'm curious how can we analyze this situation mathematically, i.e the equations of the motions of these particles...

Can someone just confirm if I'm doing these two problems correctly ... 1. How much energy is needed to place 4 positive charges, each of magnitude +5mC, at the vertices of a square of side 2.5cm 2. Choose one way of assembling the charges and calculate the potential at each empty vertex as...

Homework Statement 4 identical charges each equal to Q are placed at the 4 vertices of a regular triangular pyramid of each side equal to 'a'. Find the net electrostatic force on anyone charge. Homework Equations F = kQ^2/a^2 The Attempt at a Solution find the force due to each...

Homework Statement These are really frustrating because they seem so simple, I work them all out without a hitch only to find that I'm wrong half the time and left wondering why. In fig 21-26a, particles 1 and 2 have charge 20 microcoulombs each and are held at separation distance d = 1.5...

Why is there no equation for solving for the magnetic field produced by multiple charges in free space? To solve for this do you sum up all the magnetic fields produced by each of the point charges or what?

Homework Statement Charges 1 and 3 in the figure below have the same mass and the same speed. Which has the greater magnitude of charge? What are the signs of the charges? http://www.webassign.net/colfunphys1/21-p-001.gif Homework Equations F = |q|v*B*sin(θ) The Attempt at a...

Hi, I just remembered a question I have wondered about for countless of years without finding any answer to: Have (any of) the electric charges of quarks been empirically measured/tested/verified? (Yes, I know about the Standard Model and what the charges are supposed to be, that's not...

I'm reading the fundamentals of organic chemistry these days and I'd like to make sure I get the following absolutely right: 1) If a certain atom in an ion or a molecule etc has a formal charge of zero then the atom itself has no charge on itself irrespective of whatever the charge might be...

Four charges are placed at the vertices of a square, centered at the origin, as shown in the diagram. If each side of the square has a length of 0.224 m, what is the strength and direction of the net electric field at the origin? Express your answer in terms of the charge magnitude q...

Homework Statement An electrically neutral model airplane is flying in a horizontal circle on a 2.5-m guideline, which is nearly parallel to the ground. The line breaks when the kinetic energy of the plane is 50 J. Reconsider the same situation, except that now there is a point charge of +q on...

Homework Statement Two charges Qa = 3 µC and Qb = -2 µC are placed on the x-axis with a separation of a = 25 cm. (a) Find the net electric field at point P, a distance d = 7 cm to the left of charge Qa. (b) Find the force on Qb due to Qa . The charges Qa and Qb are now attached to the...

Homework Statement Two test charges are located in the x–y plane. If q1 = -2.75 nC and is located at x = 0.00 m, y = 0.800 m and the second test charge has magnitude of q2 = 3.20 nC and is located at x = 1.00 m, y = 0.400 m, calculate the x and y components, Ex and Ey, of the electric...

I want to understand how to compute (or find a database for) partial charges, which I can then apply to calculating coulombic interactions. From http://www.chemaxon.com/marvin/help/calculations/charge.html, it is said that electronegativity is related to the partial charge by a quadratic...

Homework Statement Take two charges, one positive with charge q+, and another with charge q- are at a distance d away from each other. Under what conditions is there a point of equilibrium and, if it exists, where would it be located? Show mathematically. (Hint: use the quadratic equation...