Potential Definition and 1000 Threads

Suppose we have a scalar function θ(x,y,z,t) of space and time where theta is some angle (0≤θ≤2π) that represents the compact coordinate of a 3 dimensional space (x,y,z) filling membrane at the space time point (x,y,z,t) in a compact space dimension w. Suppose that charge density "pushes" on the...

Homework Statement A straight copper wire that carries a sinusoidal current with an alternating frequency of 50 Hz and a maximum amplitude of 0.5 A passes through the centre of a circular ring of a second copper wire, with the two wires orientated perpendicularly to each other. The radius of...

Homework Statement In a TV tube, an electric potential difference accelerates electrons from a rest position towards a screen. Just before striking the screen, the electrons have a wavelength of 10×〖10〗^(-11) m. Find the electric potential difference. Homework Equations ∆E_K=q∆V λ=h/mv The...

Homework Statement Homework Equations C = Q/V The Attempt at a Solution Q1 = Q2 C1*V1 = C2*V2 2*V1 = 5*V2 V2 = 2/5*V1 V1+V2 =100 7/5*V1 = 100 V1 = 71.4 V Can someone verify my working? Thanks!

As I understand it, electrical potential is the potential energy of a unit charge in some point in space. How does this idea relate to the idea of voltage in a circuit? The term electric potential seems to be used for both.

Homework Statement You’ve decided to protect your house by placing a 5.0 m tall iron lightning rod next to the house. The top is sharpened to a point and the bottom is in good contact with the ground. From your research, you’ve learned that lightning bolts can carry up to 50 kA of current and...

A consequence of Coulomb's law is that oppositely charged particles have a negative potential energy. I'm having trouble undsrstanding how anything can have a negative potential energy and what consequences that has. Does it just mean the change in potential energy is negative or is it a matter...

well, we say that an object on Earth has a potential energy that is dependent on its position, i.e height. In this case we take Earth as reference point, similarly if we take sun as reference point, the Earth should have some sort of potential energy.

Homework Statement Homework EquationsThe Attempt at a Solution Apologies for the question image not being very clear . I will refer capacitors by numerical value of their capacitance . The 6 , 4 , 8 capacitors are in parallel . 9 , 9 , 7 are shorted out .So , we can remove them from the...

Homework Statement Homework EquationsThe Attempt at a Solution U = 5x2 - 20x F = -dU/dx F = -10x + 20 The expression for force doesn't look like motion is SHM . How should I deal with this ?

What is the energy gap between the ground state (n=0) and the first excited state (n=1) of an electron trapped in a deep rectangular potential well of width 1Å?

Hello everyone, I found this article that explains how some sorts of radiation treatments could be controlled with positron-emission tomography (PET). A team of researchers, led by Professor Samuel Achilefu from the Washington University School of Medicine’s departments of radiology and...

Not talking about crypto-currencies, but the technology itself. the standard argument one hears is something like 'bitcoin may be a scam, but blockchain represents a revolutionary breakthrough that will change the world' Asking about the technology itself, will it really become the backbone...

Homework Statement A hollow circular cylinder, of radius a and length b, with open ends, has a total charge Q uniformly distributed over its surface. What is the difference in potential between a point on the axis at one end and the midpoint of the axis? Show by sketching some field lines how...

Homework Statement For the cylinder of uniform charge density in Fig. 2.26: (a) show that the expression there given for the field inside the cylinder follows from Gauss’s law; (b) find the potential φ as a function of r, both inside and outside the cylinder, taking φ = 0 at r = 0. 2...

Hi. In all of my question, I mean degrees celsius when I say degree. Think we have a 0 degree ice. we give some energy to it (by a heater) and all of it get into a 0 degree water. How does the kinetic and potential energy of the molecules change? In the book in which I saw this question, it...

Homework Statement A spherical shell with radius R and surface charge density σ is sandwiched between two infinite sheets with surface charge den- sities −σ and σ , as shown in Fig. 2.46. If the potential far to the right at x = +∞ is taken to be zero, what is the potential at the center of...

Homework Statement The electric field inside a parallel plate capacitor is measured to be E= -3500 N/C i. The electric potential at point XA = 3.00 m is measured to be 1500V. What is the electric potential at point XB = 0 m? Homework Equations V=E⋅s The Attempt at a Solution I think I need to...

Homework Statement A charge of 2 C is located at the origin. Two charges of −1 C each are located at the points (1, 1, 0) and (−1, 1, 0). If the potential φ is taken to be zero at infinity (as usual), then it is easy to see that φ is also zero at the point (0, 1, 0). It follows that somewhere...

Homework Statement I am being asked to show that the wave function ψ and dψ/dx are continuous at every point of discontinuity for a step potential. I am asked to make use of the Heaviside step function in my proof, and to prove this explicitly and in detail. Homework Equations...

Homework Statement Consider the system of two charges shown in Fig. 2.8. Let z be the coordinate along the line on which the two charges lie, with z = 0 at the location of the positive charge. Make a plot of the potential φ (or rather 4πε0φ, for simplicity) along this line, from z = −5 m to z...

Hello, I'm current studying magnetostatics and I'm struggling to understand the equation for A. Here is the equation from Griffith in the attachment. My confusion is, if the object is a cylinder and the current density is a function of s, J(s), then how would I write r-r'? Thank you!

So here is how my book defined electric potential. If you take a charge, it will have a corresponding electric field associated with it. If you put another charge in that electric field, an electrostatic force will act on it and give it kinetic energy. This kinetic energy can't come from thin...

<<<Moderator's Note This thread was split form https://www.physicsforums.com/threads/are-the-terminals-of-a-battery-neutral.939947/>> because the grounding posts are interesting but off-topic to that other thread.>> The entire Earth (ground) might be charged plus or minus one million volts...

Homework Statement An Ohmic material with some conductivity has a uniform current density J initially. Let's say the current is flowing in the direction of the z-axis. A small insulating sphere with radius R is brought inside the material. Find the potential outside the sphere. Homework...

What exactly is this potential energy? I was searching and its looks like electric potential energy (U = K*Q*q/d - K*Q*q /d0), because the two atoms attract each other that means that the product of Q*q = negative, so, a negative energy. Ok, that's make sense, but why when the repulsive forces...

I am having a doubt that if Id lho potential is Given of the form λ2px2/2m+.5kx2 then whether the ground state energy of the system is λ2/4ħω+1/4ħω

Homework Statement B is 10kg C is 20kg can I find a lagrangian for this system? If so how? Diagram: http://imgur.com/j811rzw Homework Equations L=T-V Kinetic = .5mv^2 Potential = mgh The Attempt at a Solution I know the kinetic energy must be 0 right? How could I find the potential?

Images aren't embedding properly, so forgive the urls. This is the question I am attempting to answer: https://imgur.com/a/mEcAl and this is the start of my answer: https://imgur.com/a/8MoDi so.. I wasn't expecting just to get the coulomb potential at the end. This is supposed to be the...

So I understand that a capacitor consists of 2 plates separated by a distance which creates a potential difference between the plates. But I was confused, when watching this physics video it seemed to be saying that once the capacitor was fully charged, the plate closest to the positive terminal...

I've never been given a clean cut explanation of ground. I've heard some people refer to it as a common return path for current. Another as being a relative point that has a potential of 0V. Sometime people say Earth ground which I'm pretty sure actually means the ground of the Earth (not...

I'm trying to understand what exactly it means in terms of the voltage of a battery. I know that the voltage in a battery is just the potential difference between the two terminals. But, is the negative terminal used as a relative point and seen as 0? If that's the case does 12V mean that the...

I often hear scientist say that generally the effect of a weak perturbing potential on the ground state of a system is larger than its effect on higher states and that the strength of the weak perturbation on the states decrease as we go higher in energy. For example, if a weak potential is...

So in my physics textbook a problem is stated. We are given an external electric field directed downwards of 150N/C. We are then told that an electron is released in the electric field and it moves upwards 520m. Finally we are asked to calculate the change in electric potential energy of the...

Homework Statement Problem 1.24 (this is unimportant; it's just a different way of calculating the potential energy of a solid cylinder) gives one way of calculating the energy per unit length stored in a solid cylinder with radius a and uniform volume charge density ##\rho##. Calculate the...

Homework Statement :[/B] This is isn't exactly a problem,but actually something i don't understand in the book i was following, so there this art. about 'Principle of a Generator', whose description is given as, " A generator is an instrument for producing high voltages in the MeV range. Its...

I'm stuck with a solution to the vertical spring with a body suspended. The solution says that when the body's gravitational potential energy is decreasing, the spring's potential energy must be increasing. How is this correct? I understand the analysis leading to the result that the vertical...

I am solving a problem where I need to decide if an asteroids velocity is high enough to escape the planets gravitational pull. The way I did it was use conservation of energy and angular momentum to find an expression for the radial velocity and show that it remains positive as r tends to...

Homework Statement Hello, I'm trying to solve laplaces equation to find a solution for the potential in a pipe with the given boundary conditions: at x=b, V=V_0 at x= -b, V = -V_0 at y=a, V=0 at y=-a, V=0 (Assume this configuration is centered on the origin, pipe as dimensions -b<=x<=b...

Homework Statement Find the distribution of charge giving rise to an electric field whose potential is $$\Phi (x,y) = 2~tan^{-1}(\frac{1+x}{y}) + 2~tan^{-1}(\frac{1-x}{y})$$where x and y are Cartesian coordinates. Such a distribution is called a two-dimensional one since it does not depend on...

Can someone explain the math of how potential energy travels from higher potential energy to lower potential energy (PE) along a uniform electric field? I understand that in order for the point charge to move, gaining kinetic energy, it will lose potential energy. But using the equation...

Hi everyone. I've been doing a lot of reading regarding electric potential and electric potential energy. Unfortunately, I have a lot of confusion regarding this topic, as I keep receiving different information. My main confusion is regarding the signs, positive or negative, of work and it's...

Homework Statement Homework EquationsThe Attempt at a Solution In the region |z|<1 , E(z) = -dV/dz = 10zk This means there is a variable electric field in the region -1<z<1 .In the +z region it is directed in the +z direction and vica versa . For finding the charge density in the region...

Four identical particles, each having charge q and mass m, are accelerated from rest at the vertices of a square of side L. How fast is each particle moving when their distance from the center of the square doubles? I used the Conservation of Energy => Kf= -deltaU = Ui-Uf 4(mv^2 /2) = kq^2...

Homework Statement A 95-kg mountain climber hikes up a mountain to an elevation of 5000 m. What is the change in the climber's potential energy? Homework Equations I might be missing something but here's everything that might be relevant: w=fx p=w/t p=f*v KE=1/2mv^2 PEg=mgh PEe=1/2kx^2 Wnet=E...

Does potential difference only indicate how much energy each coulomb have, or make current flow, or do both?

Okay...I got a question. Charges move in a wire due to an electric field across its ends. Now, positive test charge in an electric field would have higher electric potential nearer to the positive plate than anywhere else. Now in case of a circuit, like the one I have drawn, the electric...

I'm reading up on the Lagrangian equation, but what I'm asking is to do with electromagnetism. In the first equation here: http://www.phys.ufl.edu/~pjh/teaching/phy4605/notes/chargelagrangiannotes.pdf L equals the kinetic minus the potential energy. For the potential energy term, I just don't...

Homework Statement [/B] A small cube, with a mass of 2 kg, slides along a frictionless horizontal surface at a constant speed of 20 m/s until it collides with, and sticks to, a large wooden 5 kg block. The large block is attached to the left end of a spring with a spring constant of 75 N/m as...

Homework Statement I'm trying to solve problem a problem of complete energy of doubled pendulum (2 mathematical pendulums connected by a string). For a kinetic energy I would get (1/2) J(w_1)ˆ2 + (1/2) J(w_2)ˆ2 and for a potential energy of a spring (1/2) k (ϕ_1-ϕ_1) What about gravitational...