Charges Definition and 1000 Threads

Homework Statement Consider two equal positive charges (q=+2.0 µC) a distance of 3.0 cm apart. What is the electric potential midway between the two charges? What is the E field at this point? I got the work and everything all solved out, i just don't know where some of the numbers came...

I read an article on Coulomb's law which read, ''Coulomb's law only applies to point charges'' (or something along those lines). Am I wrong, or is there an equivalent that can work for magnets/big electric charges?

I would like to make an electronic electroscopes based on following concept, but its design cannot determine whether the charges are positive or negative. Does anyone have any suggestions what kind of components I can add into this device to determine the charges? Thanks in advance for any...

Im reading Peskin&Schroeder, chapter 20, the one that describes the Standard Model. I got the general idea, symmetry breakings and so on, but I am getting quite confused when starting to go to the first mathematical details. My doubts are when, in eq 20.69 defines Q=T3+Y and then forces that...

Homework Statement A point charge −3 pC is concentric with two spherical conducting thick shells, as show in the figure below. The smaller spherical conducting shell has a net charge of 22 pC and the larger spherical conducting shell has a net charge of 18 pC. 1-4)Answer in units of...

Homework Statement A -2 μC charge and a 10μC charge are separated by 15.0cm. At what point is the electric field zero? At what point is the electric potential zero? Homework Equations E=(kq1/r1^2)+(kq2/r2^2) V=kq1/r1 + kq2/r2 The Attempt at a Solution My main problem is with...

Two particles each have a mass of 7.7 x 10-5 kg. One has a charge of +5.9 x 10-6 C, and the other has a charge of -5.9 x 10-6 C. They are initially held at rest at a distance of 0.91 m apart. Both are then released and accelerate toward each other. How fast is each particle moving when the...

Coloumbs Law & Charges. Please help! :( Homework Statement A charge of +2.0 nC and a charge of +8.0 nC are separated by 36.0 cm. Find the equilibrium position for a −2.0 nC charge as a distance from the first charge. Answer in units of cmHomework Equations q/r^2 The Attempt at a Solution I...

Homework Statement Two point charges Q and -Q are separated by a distance d. The point p forms an equilateral triangle with the two charges of side length d. Find the magnitude and direction of the electric field at point p. What is the electric potential at P? Then, a charge of 2Q is placed...

Hey all, I am using the Joukowski transform to calculate the electrostatic potential and streamlines around an elliptical cylinder. The flow is caused by two point charges (one positive, one negative). My idea was, of course, to first solve the problem for a circular cylinder, and then...

Homework Statement The drawing shows two positive charges q1 and q2 fixed to a circle. At the center of the circle they produce a net electric field that makes an angle 28.6° with the vertical axis, measured counterclockwise. Determine the ratio q2/q1. [the drawing shows a circle with two...

The question is rather old but I am not sure if we have a final conclusive answer (I was not able to figure it out for myself, nor have I found consensus in the literature) 1) do free-falling charges in a static gravitational field radiate? 2) do charges at rest in a static gravitational...

Homework Statement Three charges are distributed as follows: http://tinypic.com/r/1fviq0/5 How much work must an external force do to move them infinitely far from each other? Homework Equations W = -\DeltaU = (kq_{1}q_{2})/r The Attempt at a Solution So what I did was find...

Homework Statement For each of the following arrangements of two point charges, find all the points along the line passing through both charges for which the electric potential V is zero (take V = 0 infinitely far from the charges) and for which the electric field E is zero. (Use the...

Positive or negative charges? Does anyone have any suggestions? Thanks in advance for any suggestions

Homework Statement Point charge A of mass m for which q=-Q is held in place as point charge B of mass m for which q=+Q is released from rest at a distance x. What is the speed of charge B as it collides with charge a? (This isn't an actual problem we have, just something that I was wondering...

Homework Statement Hi. :) I'm supposed to balance the formula and write the values. Cr3++CIO3-+H2O → Cr2O72-+Cl-+H+ Specify:Amount of electrons and: Charges The Attempt at a Solution I don't really got any clue. Please help! Cr3+ have +3 The oxygen have -2 and then? Cr3++CIO3-+H2O →...

HELP I don't understand at all Homework Statement Two positive point charges on the y-axis, each of which has a charge of 5.0 10-9 C, are located at y = +0.60 m and y = -0.60 m. Find the magnitude and direction of the resultant electric force acting on a charge of 7.6 10-9 C located at x =...

1. What is the magnitude and direction of the electric field strength midway between a +60uC charge and a -30uC charge, if the charges are 2.0m apart? 2.E=kQ/r^2 3. E1=Kx-30u/1 E2=-2.75x10^5 E2=kx60u/1 E2=5.4x10^5 Etotal=E1 + E2 ----> 2.7x10^5 N/C towards the - charge (my book says i have...

Three negative point charges lie along a line as shown in the figure. figure: http://tinyurl.com/7xppvc8 Find the magnitude and direction of the electric field this combination of charges produces at point , which lies 6.00 from the charge measured perpendicular to the line connecting the...

Homework Statement 4 charges, distributed as follows 12*10^{-6} C @ (-4,4) 12*10^{-6} C @ (4,4) -6*10^{-6} C @ (-4,-4) -3*10^{-6} C @ (4,-4) Calculate the potential at the origin if the potential at infinity is zero. Homework Equations V= U/q = -W/q = ∫E*dl = k*q/r...

Homework Statement Two point charges of magnitude +10 μC each are placed 0.2 m away from each other. a) How much work is done in placing the second charge? b) Is there any point at which the electric field and electric potential are both 0? Homework Equations Work = (charge of first...

Hey there! I don't understand how this really works. With each region, how is it that the charges carry over...? The answer is the fourth region. I'm just totally lost, please explain to me. :)

Homework Statement Two point charges, 3q and q lie along x-axes. 3q is at 0.00 m and q is at 3.0m. Find the point between the 2 charges at which the net force on charge q is zero. Homework Equations F=kq1q2/r^2 The Attempt at a Solution Really can't figure this one out. Missed the...

Electric Potential ! Homework Statement Two charges are placed at the corners of a square. One charge, 4.0μC, is fixed to one corner and another, -6.0μC, is fixed to the opposite corner. What charge would need to be placed at the intersection of the diagonals of the square in order to make...

Hey everyone, thanks for taking a look at this. I was hoping you could look over this to make sure I solved this correctly. Thanks for you time. Homework Statement ---- "+" ---- "+" ---- "-" ---- Given this configuration of charges where the plus and minus indicate the magnitude of...

Homework Statement Two 3.0g spheres on 1.0m-long threads repel each other after being equally charged, as shown in the figure. Homework Equations F = k*q1*q2/r2 The Attempt at a Solution sin 70° = Ty/T T = (m*g)/sin 70° T = 0.003*9.81/sin 70° T = 0.03132 N Tx = T*cos 70° Tx =...

Homework Statement The figure shows five point charges placed on a line, at intervals of 1 cm. For what values of q1 and q2resultant electrical force exerted on each of the three charges is zero? Homework Equations I imagine the law of coulomb is used here, however, I'm not sure how I'm...

Homework Statement 1. Charge q1= 1.00*10^-9C is located +0.01 m from the origin along the x-axis. Charge q2= 2.00*10^-9C is located +0.03 m from the origin. What is the electric force exerted by these two charges on a third charge, q3= 1.5*10^-9C, located at the origin? a. 1.65*10^-4N...

Problem: a charge +Q is located at the origin and a second charge, +4Q is at a distance d on the x-axis. where should a third charge, q, be placed, and what should be its sign and magnitude, so that all three charges will be in equilibrium. attempt: I don't know how to solve it fully, but...

Homework Statement Two identical 8.5 point charges are initially 4.5 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 2.0 . Homework Equations...

Homework Statement A charge, Q2 = -7.00x10^-6 C, is 8.00 cm to the right of charge Q1 = 6.00x10^-6 C. Where can a third charge be placed, along the line connecting Q1 and Q2, such that it experiences no net force? Give distances relative to Q1 and use a plus sign if the third charge is to the...

If I have a spread of electrical charges contained inside a Gaussian surface, and if I cause those electrical charges to move at relativistic speeds, the electric fields of those charges should be subject to relativistic contraction. What happens then to electric flux that cuts through that...

Homework Statement Calculate the net charge on a substance consisting of a combination of 5.4 1013 protons and 4.2 1013 electrons. Homework Equations I subtracted the two but i still had the wrong answer The Attempt at a Solution 9.6E13 1.2E13

Homework Statement What is the electric force between a glass ball that has +2.8 µC of charge and a rubber ball that has -4.8 µC of charge when they are separated by a distance of 4.5 cm? Homework Equations F=k*Q1*Q2/r^2 The Attempt at a Solution -59.6507 -8.8888888.889 4.4380e12

3 points (a,b and c) and two identical positive charges. How do you find MAGNITUDE of the electric field at the 3 points? I just need to rank them, don't need numbers. all points are on the x-axis: A (x=0); charge +Q(x=1); B (x=3); c(x=4); charge+Q(x=5) (Picture attached in the 3rd post)...

Homework Statement Three point charges lie along a circle of radius r at angles of 30°, 150°, and 270° as shown in the figure below. Find a symbolic expression for the resultant electric field at the center of the circle. Homework Equations \vec{E}=\frac{k_{e}q}{r^{2}} The Attempt at a...

Homework Statement a +70µC charge is placed 50 cm from a -50µC charge. How much work would be required to move a -.5µC test charge from a point 10 cm from the +70µC charge to a point 20 cm from the -50µC charge? Homework Equations F=k(q_{1}q_{2}/r^{2}) PE=Fd ...that's all I could get...

The result I got seemed sort of messy and I'm not sure I've gotten the basic idea correctly, so I thought I'd make it sure. I think this was the easiest problem we had to solve for charge distributions and point charges and whatnot, so I know for sure I'll have to practice more if I made any big...

Homework Statement One charge of (+5µC) is placed in the air at exactly x = 0, and a second charge (+7µC) at x = 100cm. where can the third charge be placed so as to experience zero net force due to the other charges? Homework Equations F=KQ1Q2 / D^2 The Attempt at a Solution Q1 =...

Homework Statement Two charges q = 4.0μ C are fixed in space a distance d = 4.0 cm apart, as shown in the figure. With V = 0 at infinity, what is the electric potential at point C? You bring a third charge q = 4.0μC from infinity to C. How much work must you do? What is the potential...

I have been calculating the currents and associated Noether charges for Lorentz transformations of the Dirac Lagrangian. Up to some spacetime signature dependent overall signs I get for the currents expressions in agreement with Eq. (5.74) in http://staff.science.uva.nl/~jsmit/qft07.pdf . What...

I've almost certain that I have read/ seen from MIT's OCW that the motion of a charge within an electric field does not follow the field lines. Today my physics teacher said the opposite, that the path of motion of a charge within a field will follow a field line. Who is right? And why? EDIT...

Magnetic Forces on Conductors and charges-- the motor principle An electron moving through an electric field of 475 V/m and a magnetic field of 0.1T experiences no force. if the electron's direction and the directions of the electric and magnetic fields are all mutually perpendicular, what is...

Okay, say we have one positive point charge, and one negative point charge. Their charge values are exactly opposite (q and -q). And say we place them a certain distance apart and hold them there, maybe creating something like a point-charge capacitor. These point charges can hold and transfer...

Question: Can you use a pith-ball electroscope, to determine the charge of an unknown object? Is it possible?

Hey guys, New here. It's been a while since I've done any physics. I've been playing around with some mental work in my head and I am trying to figure out why something doesn't work. I know it shouldn't work, but I can't figure out the why. What I am talking about is utilizing similar charges...

Hello everybody and merry Christmas! Here is the text of the problem which has been puzzling me for the last few days: there are two charges distant d from one another and at distance a from a conducting plane. Find the electrostatic energy of the system. The first thing I find pretty strange...

In lecture 2 of http://oyc.yale.edu/physics/physics/fundamentals-of-physics-ii/content/class-sessions , around the 50 minute mark, the professor calculates the value of an electric field at a point (x,0,0) on the x-axis of a cartesian coordinate system. (The video can be rather slow loading, so...

Homework Statement Capacitors C_1=6μF and C_2=2μF are first charged by connecting them in parallel across a 250V battery. The capacitors are then disconnected from the battery and connected positive plate to negative plate and negative plate to positive plate. Calculate their charges...