1. ### Electric field direction on a grounded conducting sphere

I am required to find the direction of the electric field on the surface of a grounded conducting sphere in the proximity of a point charge ##+q##. The distance between the center of the sphere and the point charge is ##d## and using the method of images we find that the charge of the sphere is...
2. ### Potential from point charge at distance ##l## from conducting sphere

After looking around a bit, I found that, considering the polar axis to be along the direction of the point charge as suggested by the exercise, the following Legendre polynomial expansion is true: \begin{equation}\frac{1}{|\mathbf{r} - \mathbf{r'}|} = \sum_{n=0}^\infty...
3. ### Finding the New Acceleration Given Point Charges

Homework Statement A point charge q1=15.00μC is held fixed in space. From a horizontal distance of 8.00 cm , a small sphere with mass 4.00×10−3kg and charge q2=+2.00μC is fired toward the fixed charge with an initial speed of 40.0 m/s . Gravity can be neglected. What is the acceleration of the...
4. ### Find the amount of work to move a particle from point A to B

Homework Statement How much work should be done on a point charge of q=15 nC to bring it from infinity to a distance of 3 cm from a surface of a charged sphere? Diameter of sphere is 15 cm, its surface charge density is 12 microC/cm2 Homework Equations W=deltaU=q*deltaV v=kQ/r...
5. ### Forces between the dipole and a point charge

Homework Statement We have an electric dipole with moment P=2*[/-5] pointing in x direction. What is the force experieced by dipole at origin when a point charge Q=3*[/-4] is located at (0.014 m ,0,0) Homework Equations 1. [E][/dipole]=(1/4π[ε][/0])(2p/r3) 2. p=qs 3. F=qE 4. τ=pEsinϑ...
6. ### B Notion of a zero dimensional point particle?

When we say a fundamental particle is 0 dimensional, is that literal or figurative? Is it physically possible that a particle has it's properties (like charge, mass) spread out in a finite volume, but can be "shrunk" to increasingly small volumes when we measure it?
7. ### [College Physics] Electric field and point charge

Homework Statement Around a point charge there are three points: A, B and C. Determine the electric field vector for those points. Also, determine the force vector for q0 if it was in point B. Q = 10 µC, a = 1 m, b = sqrt(3) m, q0 = 10 pC 2. The attempt at a solution Here is the attempt at a...
8. ### Magnetic Field produced by moving charges

Homework Statement I have two related questions here. 1. A positive point charge is moving directly toward P. The magnetic field that the point charge produces at P is? 2. Two positive point charges move side by side in the same direction with the same velocity. What is the direction of the...
9. ### Determining relative amounts of work done

Homework Statement Homework Equations Work = - (integral of) (E dot dl) The Attempt at a Solution Hi, I know that the right answer is D zero, but I fail to understand why. I said that the answer was A as I have different charges, and I thought that depending on how I approach each...
10. ### Find the unknown charges q1 and q2

Homework Statement The geometrical positions of point-like charges and point A situated in the xy-plane in terms of the length parameter a. The vector of electric field E at point A is shown schematically and measured as E = Exi + Eyj (that is, both Ex and Ey are given). If possible, find the...
11. ### What is the gravitational force on the 52[kg] mass

Homework Statement A particle of mass 52[kg] is at 5.0[m]ˆi a particle of mass 13[kg] is at 12[m]j, and a particle of mass 13[kg] is at −12[m]jˆ. What is the gravitational force on the 52[kg] mass due to the mass at 12[m]jˆ? answer: −1.0 × 10−10[N]ˆı + 2.5 × 10−10[N]jˆ Homework Equations...
12. ### Isolated Point Charge and Work?

This is a really abstract question, and I'm absolutely clueless on how to approach it. I know W= F*d, where F=force and d=distance, as well as W= PEa-PEb. The question reads: The diagram shows an isolated point charge. Marked are four paths (A, B, C, and D) from a point (P1) to point (P2). The...
13. ### What does it mean to say a battery is however many volts?

For instance, at a point 1 meter from a 1 nC charge the voltage (potential difference) from the formula V = Kq/r, is given as 9 volts, 9 J/C. So what does it then mean to call a battery 9V, 9 J/C? Is this a battery capable of taking a 1 C charge from infinity and pushing to within 1m of a 1 nC...
14. ### Finding the electric field at point P between two charges

Homework Statement Find the electric field (both magnitude and direction) at point P located between the charges q1 = -3C and q2 = +4C. Point P is 1/3 of the charges' separation distance from q1 and 2/3 of the charges' separation distance from q2. Homework Equations E = kq/d^2 Etotal = E1 + E2...
15. ### Calculating Electric Field due to two point charges.

Homework Statement Two points charges. q1=2.4e-6 C is located at (0,0) q2=-5.7e-6 C is located at (3,0) I must calculate the magnitude of the Electric field at (0,0) Homework Equations E=kq/r^2 ; k=9e9 The Attempt at a Solution The electric field at (0,0) due to q2=9e9x(-5.7e-6)/3^2 =...
16. ### Electric Fields: Oscillating point charge

Homework Statement Reading a journal from that crazy old retired physics professor on the hill, you stumble upon a scheme to generate high frequency (HF) radio waves (λ = 10 m). It requires generating an electric field that diverges from a point and increases in strength linearly with respect...
17. ### Electric Fields and Charges Fill in the blanks

Homework Statement [/B] Select the answers which complete the statements below (e.g., if answer A completes the first statement, and answer B the others, enter ABBBB). A) positive B) negative C) neutral D) cannot tell A positive point charge is brought near the outside surface of a...
18. ### Point Charge Given Field Maps

Homework Statement The electric field map is shown below. (Take it to be a self-consistent scale drawing at a particular moment in time.) where \mathrm{q}_4 = +10 C, \mathrm{q}_6 = +10 C What is the charge of \mathrm{q}_5 ? Homework Equations The Attempt at a Solution I've tried the...
19. ### Electric Field of Point Charges in Equilateral Triangle

Homework Statement A point charge q =+6.4 \mu \mathrm{C} is placed at each corner of an equilateral triangle with sides 0.29 \mathrm{m} in length. What is the magnitude of the electric field at the midpoint of any of the three sides of the triangle? Hint: if you are careful to examine the...
20. ### Electric potential of a cube of 8 point charges

Homework Statement Find the Electrostatic potential energy of a cubical configuration of point charges. (One charge on each corner of a cube). Each of the charges is 3.00e and the edge of the cube is 3 cm. Homework Equations U = kqQ/r The Attempt at a Solution I'm pretty sure I understand...
21. ### Find the potential difference in a rectangle

Homework Statement [/B] Figure 20-3, referred to below, is 0.800m wide and 0.400m tall with "A" in the top left corner, "+4 microC" charge in the top right corner, "+2 microC" charge in the bottom left corner, and "B" in the bottom right corner. Two point charges of magnitude +4.00 μC and...
22. ### Electric Flux through a sphere from a point charge

Homework Statement I need to create an equation that can tell me the electric flux through the surface of a sphere (centered at the origin) due to a point charge placed at various locations in/around the sphere. For example, find the electric flux through the sphere (of radius = 1) with a point...