Coulomb force Definition and 44 Threads

  1. A

    B Understanding the electric field

    I’ve been trying to get the proper understanding of electric field. Fine I get the definition: any charge changes space around itself and thus generates electric field that acts with force on any object that’s relatively close to the charge. But first from the first, how can the FIELD act with...
  2. Lotto

    What minimum speed do we need to give a charged ball?

    First, if we sign the speed in the highest point of the ball's trajectory to be ##v_2##, we can write ##m\frac {{v_2}^2 }{l}=T_2+mg-\frac{1}{4\pi \epsilon}\frac{Q^2}{l^2}##. Now, depending on the ball's particular mass, the electrostatic force can be bigger of smaller than its gravity force...
  3. ValeForce46

    I Separation energy of nucleons and Coulomb barrier

    My professor and the book I'm reading (Particles and Nuclei: An Introduction to the Physical Concepts by Povh et al.) says that "The emitted nucleons are primarily neutrons since they are not hindered by the Coulomb threshold" which means that a neutron has a separation energy lower than a...
  4. DanielGuh

    Coulomb's Law Application: A charge repelling a mass on a frictionless incline

    Fg = Fc Fg = 2.3g*9.8m/s^2*cos(28)=19.90N 19.90 = (8.99*10^9)*(4*10^-6)*(6*10^-6)/(r^2) 1/(r^2) = 92.23 r = 0.104m However, it's not one of the option...
  5. K

    Modelling an interation between two protons

    The image given with the problem: I found the original problem too difficult to solve, so I thought I'd make it easier by first considering the stationary proton as fixed in place. However, this too proved to be way more difficult than I expected. Here's the updated diagram I used in my attempt...
  6. M

    Question on Calculating Coulomb force in VECTOR FORM

    The only thing tripping me up here is that the answer needs to be in vector form. If the question was asking for the scalar form, then I would just find the distance between the charges (plot the charges according to their vector coordinates, then use pythagorean theorem to find the distance...
  7. A

    B Coulomb Force: Is my understanding correct?

    In a bound state like atom nucleus (except H-1), protons carry a positive charge so repel each other by the Coulomb force. This type of electromagnetic force, (also referred to as electrostatic repulsion) is an inverse-square force (has infinite range characteristics), so a proton added to a...
  8. O

    Balancing forces on charged balls hanging on strings

    Answer says, 'any (x, y) satisfying 2(a^2)x = (x2 + y2)^(3/2)
  9. J

    B Coulomb force over Rindler horizon

    Let's say a rocket carrying a positively charged balloon starts to accelerate with a constant proper acceleration at time t. After a long time another rocket carrying a positively charged balloon is launched. The crew of this rocket drives the rocket to a position right below the...
  10. Mutatis

    Net force acting on a charged particle ##+Q##

    Homework Statement Twelve equal particles of charge ##+q## are equally spaced over a circumference (like the hours in a watch) of radius R. At the center of the circumference is a particle with charge ##+Q##. a) Describe the net force acting over ##+Q##. b) If the charge located at...
  11. astroman707

    How Do You Calculate the Electric Charge on a Suspended Cork Ball?

    Homework Statement A cork ball is suspended at an angle from the vertical of a fixed cork ball below. The mass of the suspended ball is 1.5x10^-4 kg. The length of the suspension thread is .1m. The fixed ball is located .1m directly below the point of suspension of the suspended ball. Assume...
  12. A

    B Is the Coulomb Force Limited by the Pauli Exclusion Principle in Hydrogen Atoms?

    Can charges collapse under coulomb attraction like charge-less matter does under gravity? In a way it's similar to asking about the lower limit of coulomb force if there is any. Also, does Pauli exclusion principle save the day just as in the case of gravity?
  13. starstruck_

    Calculating total Coulomb force vector ?

    Homework Statement Consider a configuration consisting one +q charge ( upper right) and three −q charges, arranged in a square. Side lengths = d. Calculate the total F force vector acting on charge +q.Homework Equations Vector form of culomb’s force F=( kq1q2/r^2) rhat (rhat for unit...
  14. P

    Coulomb force and charge equilibrium on the xy-plane

    Homework Statement Two point charges q and 4q are located at r1 and r2, respectively, on the xy- plane. The magnitude Q and location R of a third charge to be places on the plane such that the total force on each of the three charges vanishes, are? first i plotted the problem on the xy...
  15. K

    Paradox - different results for different viewers

    Homework Statement One person that we will call him - A is standing on an infinite charged non conductive panel with velocity V=(-Vx0,0). A is throwing a particle q with V=(Vx0,Vy0). The other person - B, is start running below the particle at t=t0. A thinks that B will see the particle above...
  16. Z

    Coulomb's force - magnitude of the electric force

    Homework Statement Show that the magnitude of the electric force on each ball is given by Fe = mgtanθ/ (cosα+ sinαtanθ) where θ = arcsin(x2/L) α = arcsin((y2-y1)/r) r = √((x2-x1)^2+(y2-y1)^2) This is a question from my coulomb's law lab, where 2 styrofoam balls where charged, one was hung on a...
  17. sweet springs

    What propagates changes of Coulomb force?

    Hi. Say a positive charge is at (x,y,z)=(0,0,0) at t<0 then (1,0,0) at t>0. Electric field at (x,y,z)=(l,0,0) is (a,0,0) at t<l/c then (b,0,0) at t>l/c thus a<b. With time delay of l/c, what propagates from (x,y,z)=(0,0,0) to (l,0,0) ? I do not think it is electromagnetic wave because it is...
  18. F

    Natural frequency of 3 coulomb force bound particles in EF

    Homework Statement I was given a task to model (using Matlab) 3 identical particles in external field and find spectra of lowest system energy states using gradient descend method for each particle in the system. I did a run of 500 random generated coordinates and found this distribution...
  19. Q

    Kinetic Energy Gain due to Coulomb Force

    Homework Statement Hi guys! I have a problem pertaining to the kinetic energy gained by a point charge from interacting with a another point charge. Here's the problem: A point charge of mass m1 and charge q is placed near another point charge with mass m2 and charge Q. Both charges are of...
  20. M

    Coulomb force and the self electric field

    The well-known connection between the electric field and Coulomb's law is that The magnitude of the electic field at distance r from a point-charge Q is E=Q/r^2The definition of E is that the force exerted the field on a point-charge q is F=qE. These two equalities yield the F=qQ/r^2...
  21. A

    Hooke's law and the Coulomb force

    Homework Statement An unstrained horizontal spring has a length of 0.32 m and a spring constant of 220 N/m. Two small charged objects are attached to this spring, one at each end. the charges on the objects have equal magnitudes. Because of these charges, the spring stretches 0.020 m, relative...
  22. B

    Very hard Coulomb Force with two charges

    I'm new to forums and after I typed all this out and tried to submit, it cleared everything. I really need to get this problem finished tonight. Homework Statement You have two charges (q1 = -15uC and q2 = 3uC) separated by a distance (d = 3m). We want to calculate the electric field, E...
  23. P

    When should I consider the sign of charges when applying Coulomb's Law?

    I am studying Physics Vol2 by halliday, resnick and krane. I was attempting the coloumb force exercises..If we put one charge negative and other positive in the formula..then the force comes out to be negative but the instructor manual for the book ignores the negative charge, and take it as...
  24. T

    Understanding Coulomb Force in Plasmas

    This may be a pretty dumb question. How is it possible for ions and electrons to coexist in plasma state. Shouldn't be there Coulomb force between them so that they would be bound together and become atoms?
  25. J

    Coulomb force if dielectric is placed in between them

    Homework Statement two charges q1 and q2 are palced at a distance r. A slab of thickness t is placed between the two cahrges having dielectic constant k. Find coulomb force between the charges. Homework Equations Well F = q1q2 / 4∏ε°k - this would have been the force if the slab was...
  26. Gamma

    Tedious Algebra- Is it needed? - Coulomb Force

    Hello, A typical problem assigned to students is where there are two charges on the x-axis and find the location of a third charge so that the net force on it is zero or some other force value given. I am wondering what is the idea behind this problem? It can get really complicated when...
  27. F

    Is There Any Significant Difference Between Gravitational and Coulomb Forces?

    The definition of Δ (difference,drop of) Electrostatic Potential Energy (D E-PE) says it 'is the work done on a unit charge (e) to bring it from r to r1 (against the force) with constant (without acceleration) velocity and extremely low absolute value of velocity (quasistatic, vanishingly...
  28. W

    Coulomb Force Point Charges on Cube

    Hello, I'm having a little trouble with this: Coulomb Force Point Charges on Cube Homework Statement Identical charges of Q (C) are located at the eight corners of a cube with side L (m). Show that the coulomb force on each charge has magnitude: 3.29Q^2/4\pi\epsilon_0l^2 Homework Equations...
  29. H

    Coulomb force vs. Pauli principle in atoms

    Homework Statement In the absence of the Pauli principle, the Coulomb force would not be saturated, and the energy of a system containing N atoms would vary as N^(5/3). Show that a system of 2N atoms would have an energy lower than that of two N - atom systems. Homework Equations E...
  30. P

    Deflection Angle in a Repulsive Coulomb Field

    Homework Statement Find the deflection angle of a particle moving in a repulsive Coulomb field. Homework Equations The Attempt at a Solution Hi everyone, I can do this no problem if I just knew the equation for a repulsive Coulomb field! Can anyone please help me with this? Thanks
  31. D

    The wavelength of the virtual photons of the Coulomb force

    Is there a way to calculate the wavelength, frequency or energy (per photon) of the virtual photons that charges exchange to account for the Coulomb force? This is assuming that it's always the same wavelength, of course.
  32. D

    How is the Coulomb force transmitted?

    Hi everybody, I'd like to pose a few questions that I've had for ages. I haven't found any answers except "read some Quantum Field Theory" so I'd appreciate an explanation in layman's (or in "science educated but not at all expert") terms. Suppose we have two small charges, one positive and...
  33. V

    Maxwell's equations VS. Lorentz & Coulomb force equations

    I find Maxwell's equations insufficient and superfluous having the Lorentz & Coulomb's force equations. As far as I see magnetic (Lorentz force) and electric (Coulomb's force) interaction is best defined by these two equations themselves, and although Maxwell's equations can describe quite a few...
  34. S

    Lorentz Force and Coulomb Force

    Homework Statement In frame S, two identical point charges q move abreast along lines parallel to the x-axis, a distance r apart and with speed v. Determine the force in S that each exerts on the other: a) using the lorentz force in conjunction with the field of a moving charged particle...
  35. D

    Electrostatics, coulomb force between 2 charges

    in a mass of 12g of carbon there are NA= 6.02215x1023 atoms, each atom has 6 electrons, 6 protons and 6 neutrons. each electron has a charge of -1.6x10-19C and each proton has a charge of 1.6x10-19C, each neutron has no charge. if all the electrons were at the north pole and all the protons at...
  36. Kudaros

    Coulomb force on a line charge

    Homework Statement We have a source charge that is a uniform sphere with a radius a (centered at origin) and uniform charge density, \rho. There is a line charge with a length L that begins at Z0 and ends at Z0 + L (lies on the Z axis). This line charge has a uniform charge density of...
  37. L

    Negative potential energy and coulomb force

    The coulomb force is given by k*q1*q2/r^2 so if there are two charges that have negative signs, then the force would be negative. Having said that, a "negative force" would then signal an attractive force since opposites attract. F=-dU/dx, so a negative force would result in a "positive...
  38. C

    Exploring the Mystery of Coulomb Force

    about coloumb? i wonder why two point charge whose magnitude 0 and +q(or smt different from zero charge) exert a coloumb force to one another .formula says there shoud be no force acting to each other(because of multiplication q1.q2=0) but there is an atraction between them . if this force...
  39. R

    Questions on reversed Coulomb force.

    Questions on reversed "Coulomb" force. I've seen that with Moeller scattering, the attractive force between the nucleus and the electron can become repulsive at high relativistic velocities of the electron. What are the energies required for this to occur? Is there an analogous result...
  40. R

    Questions on reversed Coulomb force.

    Questions on reversed "Coulomb" force. I've seen that with Moeller scattering, the attractive force between the nucleus and the electron can become repulsive at high relativistic velocities of the electron. What are the energies required for this to occur? Is there an analogous result between...
  41. B

    Exploring the Coulomb Force: Vectorial & Non-Vectorial Forms

    I must comment on the Coulomb force - vectorial & non-vectorial form: F=k*((Q1*Q2)/r^2 ) F=k*((Q1*Q2)/r^2 )*[r] >>>[r] unit vector I know that , in case of vectorial form, I can use superposition principle, and use this form when the direction is important for me. But what's more?
  42. S

    How Does a Uniform Spherical Charge Influence a Linear Charge Along the Z-Axis?

    A line charge of length L with lamba=const.(linear charge density) lies along the positive Z axis with its ends located at z=z0 and z0+L. Find the total force on the line charge due to a uniform spherical charge distribution with center at origin and radius a<z0 Sooo here's what I DID I...
  43. maverick280857

    Calculating the Coulomb Force between 2 charges in space

    Hi Here is an interesting problem which I have been trying to solve. For convienience of discussion, I have broken it into parts to show where I get stuck: Two charges Q_{1} and Q_{2} are kept in space at a distance r from each other in a medium of dielectric constant K. The force between...
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