Potential Definition and 1000 Threads

  1. cahill

    I Change in chemical potential energy from nuclear decay

    I have been amateur reading about beta decay. The example given for electron capture was krypton-81 into bromine-81. Going from a noble gas to a halogen gives rise to a big change in chemical potential energy. How is this energy accounted for in the equations of the reactant particles and...
  2. S

    Potential difference between the surface of a sphere and a point far away

    V at surface = k Q / r = 9 x 109 x (1 x 109 x (-1.6 x 10-19) / (1 x 10-2) = - 144 V V at a point far away = 0 V From the sentence "electric potential difference between the surface of this sphere and a point far away" means that the question asks about V at surface minus V at far away so the...
  3. Zouatine

    Question about potential for this mechanical force problem

    Hi! hope you are doing well , I'm trying to solve this problem ( mechanical problem) about structure with load F as it showing in the next figure , i want to determine to critical force F , the stability force ( which means if my load is bigger than the critical load my system will be unstable)...
  4. S

    I What force potential should I use for star formations?

    I'm running some molecular dynamic simulations and I came across this, https://en.wikipedia.org/wiki/Star_formation#Cloud_collapse , and I was wondering if there was a specific force potential to use in this case. Supposing I have a ensemble of heated atoms moving around and I cool them down...
  5. S

    Location where the electric potential is zero between charges

    a) I take "a point where it is neutral" as the electric potential at that point is zero. Is this correct? And because the two charges are both negative, there can not be any point where V = 0? Am I wrong or maybe one of the charge should be positive? Thanks
  6. M

    Potential Energy: Rigorous Understanding & E=mc²

    I used to believe that potential energy of a particular particle is of no meaning. It is always linked with a system, and Potential Energy of a system means negative of work done by INTERNAL conservative forces from an initial stage of assumed zero potential energy. And energy cannot be said to...
  7. moeug1999

    Electric Potential at A and B: Find the Answer

    I found the potential at A, however I tried doing it with B but it says I have the wrong answer.
  8. K

    I What is being plotted in the nuclear potential formula by Samuel Wong?

    Hello! In Nuclear Physics, Second Edition, by Samuel Wong he shows a plot of the nuclear potential (see attached) but he also gives a formula (also attached) for the most general way of writing the nuclear potential. In that formula, we have the coefficients depending on r only, but the overall...
  9. Saptarshi Sarkar

    I Why does Special Theory of Relativity leave out Potential Energy?

    While studying Special Theory of Relativity I came across the formula for the energy of a particle. The total energy of a relativistic particle in STR contains the Rest Mass energy and the Kinetic energy. But, in Classical and Quantum Mechanics, we consider the total energy of the particle to be...
  10. B

    Work done to reach the point where the gravitational potential is zero

    Hi there I have been attempting the parts to this question and I'm finding some trouble on how to answer the last part which is d)iii Here is what I have done for the rest of the parts and what I think I should start off with in part d)iii Thanks!
  11. K

    Determine the Electrical potential at a given point

    A rod with a circular center in the middle (which causes the rod to change direction by 90 °) has an evenly distributed linear charge density 𝜆 of electrons along the entire rod. Determine the electrical potential of the red dot in the figure below which is at the center of the circular round...
  12. Decimal

    Magnetic vector potential of a moving current sheet

    Hello, I start by applying the integral for the vector potential ##\vec{A}## using cylindrical coordinates. I define ##r## as the distance to the ##z##-axis. This gives me the following integral,$$\vec{A} = \frac{\mu_0}{4\pi} \sigma_0 v 2 \pi \hat{x} \int_0^{\sqrt{(ct)^2-z^2}}...
  13. I

    Quantum Mechanics Infinite Potential Well -- Check Answers please

    I'm self studying so I just want to ensure my answers are correct so I know I truly understand the material as it's easy to trick yourself in thinking you do! A particle of mass m is in a 1-D infinite potential well of width a given by the potential: V= 0 for 0##\leq## x ##\leq## a =...
  14. I

    Integral of relative distance–dependent potential

    I think its going to be intg(dr2)intg(exp(r^2) dr) or something like that.
  15. L

    Why Do Physical Systems Seek Minimum Potential Energy?

    Many, many years ago while in engineering graduate school I was studying calculus of variations. One classic problem was to determine the shape of a hanging cable supported at its two ends. After minimizing the integral, the catenary curve was the solution. The basic assumption in setting up...
  16. Diracobama2181

    Potential and E field for a non homogeneous charge Density

    Based on the conditions, I found that $$V(x)=\frac{a^2}{\pi^2} ρ_0sin(πx/a)$$ would be a solution to Laplace's equation for $$|x|\leq a$$ and $$V(x)=cx+d$$, where c and d are constants. From the boundary conditions, $$\frac{dV(a)}{dx}=\frac{a}{\pi} ρ_0cos(πa/a)=ac$$, $$c=\frac{a\rho}{\pi}$$ and...
  17. P

    Battery Voltage: Potential & Chemical Reaction

    I have read that the potential V = E*d for a constant electric field E, so this is related to the battery voltage of some voltage say 12v etc. Because battery will produce voltage using chemical reaction. Above two are different concepts or related? Please advise.
  18. C

    Electrical potential of a thin wire in an E field

    Assume that an infinite metallic plate A lies in the xy-plane, and another infinite metallic plate B is parallel to A and at height z = h. The potential of plate A is 0, and the potential of plate B is constant and equal to V. So, there is a uniform electrostatic field E between plates A and B...
  19. E

    Not sure why my method doesn't work: Springs, Potential Energy and Work

    I know that you can get the answer through using Fs as 18 and solving for K, then subbing it into the equation for elastic energy. I was just wondering why another method wouldn't work. I tried doing it using the concept that Work is an equal to the Change in Elastic Energy, therefore Ee=xF...
  20. S

    Finding the potential energy if force depends on both position and time

    How to find potential energy if force depends on both position of particle and time ? Suppose force is : f(r,t) = (k/r^2) * exp(-alpha*t), k, alpha = positive constants, r = position of the particle from force-centre t = time Is this force a conservative or non-conservative ?
  21. torito_verdejo

    Electrostatics: sign of the potential

    The final result will only differ in its sign, but this is crucial. Having a positively, radially oriented electric field ##\textbf{E}##, I understand that the sign of the integral should be positive (## - (- A) = A##), but it is not! How and why is this the case? A line integral where the...
  22. C

    Electrostatic potential due to a dipole

    Given here is that by geometry r1^2 =r^2 +a^2 - 2ar*cos(theta) But if we try to do vector addition then since direction of dipole is upwards then it should be r^2 =r1^2 +a^2 + 2ar1*cos(alpha) Where alpha is the angle between a and r1. I Don,'t understand how they get it by geometry
  23. C

    Why Potential Energy cannot be included twice?

    If for example I have two charged particles q_1 , q_2 with distance 'r' between them, then: The potential energy that results from particle q_1 exerting force on particle q_2 is $$ k\frac{q_1 q_2}{r} $$ If I do the same process for particle q_2: The potential energy that results...
  24. falconblade

    Changing the k constant in voltage potential equation?

    Summary:: What if you were calculating the voltage potential for a dipole, but underwater? I'm making a predictive model (in R programming) for the voltage potential at any point around a dipole. I need to be able to change parameters, one being the k constant. V=( kpcosѲ)/(r^2). Where V is...
  25. Tryhard314

    Why does the potential of A decrease when plate B is nearby?

    Summary:: if Plate A had a potential of 9V, This means as We approach a unit charge from +Infinity to A we have to do this precise amount of work Now we remove plate A, And replace it with plate B that has a potential of -9V Again that means to go from +Infinity To B we actually gain energy, or...
  26. T

    Quantum tunneling: T(E) graph for a potential barrier diagram

    This is the V(x) diagrams and what I am thinking (really not sure though) is that for the first one you the energy has to reach V2 before it can start transmitting and the graph can take off from T=0, since there is an increase in energy potential that is V2. And as the energy increases, the...
  27. R

    Vector potential of current flowing to a point from all directions

    I am having problem with part (b) finding the vector potential. More specifically when writing out the volume integral, $$A = \frac{\mu_0}{4\pi r}\frac{dq}{dt}\int_{0}^{2\pi}\int_{0}^{\pi}\int_{0}^{?}\frac{1}{4\pi r'^2} r'^2sin\theta dr'd\theta d\phi$$ How do I integrate ##r'##? The solution...
  28. n3pix

    A question about potential energy and work

    Hello, I'm confusing about the basic terms about Conservation of Energy, Potential Energy and Work. Consider that we have a mass ##M## above the ground (zero point) distance of ##y_{0}=h##. When we release the mass it will accelerate through it's way to ground. So the work is made by a field...
  29. C

    Phase space volume with a potential (microcanonical ensemble)

    I don't know how to solve that integral, and to calculate the number of microstates first, then aply convolution and then integrate to find the volume of the phase space seems to be more complicated. Any clue on how to solve this? Thank you very much.
  30. Elder1994

    The Laplacian of the potential q*exp(-r)/r

    Hello, I have a problem where I'm supposed to calculate the charge distribution ρ. I need to calculate it by applying the Laplacian operator to the potential Θ. The potential is the function: q*exp(-αr)/r I found on the internet that for this type of potentials I cannot just apply the...
  31. nmsurobert

    Potential difference: positive or negative?

    I am working out an example problem from one of my textbooks and I am a bit confused on why a value is negative. The problem asks: Calculate the final speed of a free electron accelerated from rest through a potential difference of 100 V. This is a conservation of energy problem. Ultimately you...
  32. Tryhard314

    Salt water and potential difference

    Imagine a container of salt water at 0V (Relative to ground),Now you've put in it 2 electrodes,one at +500V (Electrode A), The other at +250V(Electrode b), Normally positive ions should go to the negative electrode , and Negative ions should go to the positive electrode , But in our example the...
  33. Diracobama2181

    Virial Expansion Approximation of of Lennard Jones Potential

    I get $$B_2(T)=2\pi N\int_{0}^{\infty} (1-e^{-\beta E_0((\frac{r_0}{r})^{12}-2(\frac{r_0}{r})^6)})r^2dr$$ as the coefficient. I was just unsure how to evaluate it numerically from here. Any suggestions would be appreciated. Thank you.
  34. binbagsss

    What is the difference between gauge potential and gauge connection?

    and when are they the same thing? In quite simple terms.Many thanks
  35. M

    Yukawa Potential: Find Value of Parameter 'a

    So this is the problem: My only point of confusion right now is in what the value of a is... I'm having trouble finding it anywhere, and online stuff about the yukawa potential just states that it's a parameter. Thanks for any help! Edit: It might be worth noting that gamma equals kq1q2.
  36. QuasarBoy543298

    I Deduce if the spectrum is discrete/continuous from the potential

    I have one-dimensional problem with a one-dimensional potential I want to know the energy domains that will result in discrete energy levels and the energy domains that will result in continuous energy levels In my lecture, my professor gave the example of v(r) = 1/r (r>0) (hydrogen atom...
  37. Sofa

    Issues Determining Change in Elastic Potential Energy

    I've attached a screengrab of the problem (Specifically, Part B, as indicated in the image) and my attempt at a solution. Summarized, my thinking was based on using ##-\Delta U=\frac{Kx_i^2-Kx_f^2}{2}##. After using up all my attempts, the solution, as it turns out, was U2=4.91J. No variation...
  38. maistral

    Ergun equation for beds + rising fluid + potential energy

    I am quite familiar with the Ergun equation's formulation. My question is, do I need to subtract the potential term ΔP/Δz = -ρg/gc after the Ergun equation's own ΔP/Δz , assuming that the fluid is to be pumped upward, from the bottom of the bed to the top of the bed? I was thinking it should be...
  39. J

    Finding electric potential at a point between 3 electrodes.

    Firstly, I am not a English speaker. So I apologize that I cannot use English well.. I got a), c), e) a) at 0.5cm, E = -q/(2e_0*A) - Q/(2e_0*A) + q/(2e_0*A) = -1.4*10^7 V/m c) at 1.5 cm, E = 0 (inside electrode) e) at 2.5cm, E = -q/(2e_0*A) + Q/(2e_0*A) + q/(2e_0*A) = 1.4*10^7 V/m And I am...
  40. N

    Calculating Gravitational Forces and Potential Energy Using Newton's Laws

    For the first part, I considered the Force acting on it by all charges as given by $$\vec {F} = \Sigma_{j} \frac{m_{i} m_{j}}{\left(r_j - r_i \right)^{1.5}} \vec{r_j} - \vec {r_i} = \Sigma_j m_i \vec {g_j} $$ Where ##\vec{g_{j}}## represents gravitational acceleration of ##m_i## due to jth mass...
  41. U

    Catapult spring, Kinetic and Potential energy

    My solutions: When ball is launched horizontally, assuming its velocity is entirely in the horizontal dimension, there is no interaction of the ball with the gravitational field, thus no change in GPE, so all of the EPE (elastic potential energy ) of the spring is transferred to KE of the ball...
  42. J

    Potential sweep vs current sweep for a Polarization Curve

    Hello, I'm trying to obtain a polarization curve for a fuel cell (two electrodes in HCl). From what I've seen in literatures, current is applied and the voltage is measured. Is it still the same to change the voltage and measure the current instead? For some reason our equipment only have the...
  43. I

    Central Potential Repulsive Scattering

    I have one problem with this question that I've been struggling with. Initially, the total energy should be given by E =m1* v0^2/2 (as U goes to zero, and m2 is at rest). However, if we write r = r1 - r2, we get E = mu*rdot^2/2 + U_eff(r), U_eff(r) also goes to 0, where mu is the reduced mass...
  44. Samanko

    Potential energy of an electric dipole

    This is a problem from a textbook, and I can't solve it. I know that the equation of Potential energy of electric dipole. Since the configuration is a little bit complicated. I'm confused applying which electric fields.
  45. K

    Python Visual Python Pendulum: Solving the Forces

    Hello and thanks in advance for your help. For about a week now, I've been trying to write what should be a simple python program. The idea is first to write a program for a simple harmonic pendulum, then adapt it to a spring pendulum. However, in order to do this, I have to write the simple...
  46. M

    Find the maximum potential difference across a series circuit

    I'm not really sure what I need to find exactly. From what I'm seeing, I could give C1 the max potential difference of 125V because it has the lowest capacitance, and because V = Q/C, this means the capacitor with the highest potential difference across its plates will be the one with the lowest...
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