What is Potential: Definition and 1000 Discussions
Potential generally refers to a currently unrealized ability. The term is used in a wide variety of fields, from physics to the social sciences to indicate things that are in a state where they are able to change in ways ranging from the simple release of energy by objects to the realization of abilities in people. The philosopher Aristotle incorporated this concept into his theory of potentiality and actuality, a pair of closely connected principles which he used to analyze motion, causality, ethics, and physiology in his aPhysics, Metaphysics, Nicomachean Ethics and De Anima, which is about the human psyche. That which is potential can theoretically be made actual by taking the right action; for example, a boulder on the edge of a cliff has potential to fall that could be actualized by pushing it over the edge. Several languages have a potential mood, a grammatical construction that indicates that something is potential. These include Finnish, Japanese, and Sanskrit.In physics, a potential may refer to the scalar potential or to the vector potential. In either case, it is a field defined in space, from which many important physical properties may be derived. Leading examples are the gravitational potential and the electric potential, from which the motion of gravitating or electrically charged bodies may be obtained. Specific forces have associated potentials, including the Coulomb potential, the van der Waals potential, the Lennard-Jones potential and the Yukawa potential. In electrochemistry there are Galvani potential, Volta potential, electrode potential, and standard electrode potential. In the
thermodynamics, the term potential often refers to thermodynamic potential.
When the pendulum is released, the Kinetic Energy should be 0. When the pendulum is at the bottom/hits the rod, it should have 0 potential energy. However, I don't quite understand what happens after it hits the rod.
In the initial position the spring is previously compressed, then the block adds a force, and the spring is again deformed. I think the energy balance is incorrect; the potential energy of the spring is repeated.
e=QxV
t=Q/I
p=(QxV)/(Q/I)
=V/I
The expression I came up with for a) is the potential difference divided by current to get power but I have no idea if that is even right if someone could just prompt me in the right direction that would be greatly appreciated
My attempt:
Let ##M_e## be the mass of the Earth and ##M_m## be the mass of the person. Let ##D_{EM}## be the distance from Earth to Mars and let ##R_e## be the radius of the earth.
Defining these constants (leaving off units for brevity):
Masses in Kilograms (G is not a mass but I'll leave...
u = (9*10^9)(1.61*10^-19)^2 * (1/[3*10^-15 ]- 1/[2*10^-10])
u = 7.68*10^-14 J
but here the question. I have been taught that W= -U so shouldn't the answer be negative??
When i look up at the solution all other sources say that the W = U and therefore the answer is in postive.
I don't understand this statement about potential energy V(x) from Griffiths Intro to Quantum Mechanics, 3rd Ed.
Problem 2.1c: If V(x) is an even function (that is V(-x)=V(x)) then psi(x) can always be taken to be either even or odd.
psi(x) refers to a solution of the Time Independent...
hi guys
I am trying to calculate the the potential at any point P due to a charged ring with a radius = a, but my answer didn't match the one on the textbook, I tried by using
$$
V = \int\frac{\lambda ad\phi}{|\vec{r}-\vec{r'}|}
$$
by evaluating the integral and expanding denominator in terms of...
Hi, not really a homework question just a quick question regarding FET-transistor. If the gate potential is -4V does that mean that in the figure below that uGS is -4V. If not, what does it mean and how do you use it in a bigger circuit problem?
Each spherical shell will contribute to potential on the surface of inner shell and the same will apply to outer shell.
Due to inner shell ##V_1 = \frac {kQ} {{r_1}}## and due to outer shell ##V_1 = \frac {-kQ} {r_1}##. Therefore potential on inner surface is zero.
But the answers are ##V_1...
[Mentors' note: This thread was split off from https://www.physicsforums.com/threads/system-potential-energy-and-nonconservative-forces.1009237/]
This is not a particularly helpful way to think about things;
For a general mechanical system, you usually split the specified forces into external...
Hello,
I am trying to get my head around the idea of nonconservative forces doing work and changing the potential energy of a system.
First of all, forces acting on a system can be:
a) internal and conservative
b) internal and nonconservative (friction, pushes, pulls, thrust, etc.)
c) external...
Hello everyone,
I'm looking for help for the problem 3 of the chapter III. Schrödinger's equation, §25 The transmission coefficient of the Volume 3 of the Landau-Lifshitz book (non-relativistic QM).
In this exercise Landau considers a smooth potential wall $$\frac{U_0}{1 + \exp{\left(-\alpha x...
A question to physicists: What sort of real world scenario / image would *best* depict the increase in gravitational potential energy in a radial field?
Would a rocket traveling through the Earth's atmosphere suffice or are there better alternatives?
This image would have to be relevant to the...
hi guys i am encountered with a question that is : two protons in a helium atom stand close together,approximately at a distance of 2 fm. what is the potential energy of this system ?
i can understand the concepts that are potential of a particle or potentail of a object etc but can't...
hi guys
I came across that theorem that could be used to check if a surface represented by the function f(x,y,z) = λ could represent an equipotential surface or not, and it states that if this condition holds:
$$\frac{\nabla^{2}\;f}{|\vec{\nabla\;f}|^{2}} = \phi(\lambda)$$
then f(x,y,z) could...
Hello, any answers appreciated:
'Two spheres are 5 m apart. Sphere 1 has a charge of -20 mC and sphere two has a charge of -50 mC. (a) Find the strength of the electric field at the sphere's halfway point. (b) Find the electric potential at the halfway point
Does fermi level (in metals) depend on the density of states? I am asking this because from fermi-dirac distribution it seems like that fermi level is non-dependent of DOS, but there is chemical potential in fermi-dirac distribution, which is said to be dependent of DOS.
I'm studying nuclear physics in a text, but at one point that is said: "Both the Coulomb potential that binds the atom and the resulting electronic charge distribution extends to infinity" , I don't understand what is that "resulting electronic charge distribution extends to infinity" what they...
This problem is from David Morin's classical mechanics textbook:
I am having trouble with Part b. Here is the textbook's answer:
I do not understand why large particle energies lead to capture. I would think that smaller energies would lead to capture because the particle wouldn't have enough...
So Kirchoff's Loop law states that, The sum of all the potential differences encountered while moving around a loop or closed path is zero.
Ok so that is basically a statement of energy conservation. So I see why in the TYPED solution, they related all voltages in the circuit equal to zero. I...
Hello,
To first clarify what I want to know : I read the answer proposed from the solution manual and I understand it. What I want to understand is how they came up with the solution, and if there is a way to get better at this.
I have to show that, given a vector field ##F## such that ## F ...
I know the math behind these, and I'm happy to use more precise language if needed, I just wanted to get some input on this sweeping generalization that entropy is the conversion of potential to kinetic energy.
A brief summary of two important branches of entropy:
1) thermodynamics - the total...
So I started with b)
and it there was no q2 this would seem reasonable
I was wanted to ask , what effect does q2 have on potential of these two charges? Because it has to be given for a reason.
My solution for the vector potential ##A=2Cln\frac{x^2+y^2}{z^2} \hat{z}## is:
a) I used the following formula to calculate the magnetic field
$$ \mathbf{B} = \nabla \times \mathbf{A} = \left( \frac{dA_z}{dy} - 0 \right) \hat{x} + \left( 0 - \frac{dA_z}{dx} \right)\hat{y} + 0 \hat{z} =...
So I know that E = -ΔV/Δs. If I wanted to solve for change in potential I could rearrange this equation and get Δ = -E*ds. With that information I believe I can solve the problem below. But in both solutions provided below, the negative sign goes away. Now I know I can pull the E out because it...
Hi, I'm new here, so I don't know how to write mathematical equations, and I may not be fully aware of the rules here, so I'm sorry if I made a mistake.
I know how to calculate the electrostatic potential energy of a countable number of charged particles, but I don't know how to calculate the...
Hi!
I tried to solve it by using the equation of the electric potential above and as we see it requires the electric field, but the electric field at the center of the ring is zero. Then I tried by using the equation [text] V = \frac{1}{4\pi\epsilon_0r} \int \lamda dl [\text] and I got [text] V...
I have been having a hard time understanding Electric Potential and believe I finally have a grasp on what is trying to say. I wanted to right out my understanding here and hopefully have someone confirm what I am saying is somewhat accurate as I feel like when you write stuff out you tend to...
I read about a proposal for storing potential energy by hoisting heavy weights that can be dropped when needed to generate electric power. So using the numbers from a hydraulic turbine from Hoover dam, how heavy would a hanging weight have to be to generate 178,000 horsepower as it descended...
I set up an equation for the sum of all the potential energies and when cancelling out ##k## and ##q^2##, I got ##\frac{1}{0.05}-\frac{1}{x}-\frac{1}{0.05-x}=0##. However, this has no solutions, so I must've gone wrong somewhere. Could someone just give me a hint, not a solution, that would put...
Using the generating function for the legendre polynomial: $$ \sum_{n=0}^{\infty} P_{n}(x) t^{n}=\frac{1}{\sqrt{1-2 x t+t^{2}}} $$ It's possible to expand the coulomb potential in a basis of legendre polynomials (or even spherical harmonic ) like this: $$ \begin{aligned} &\frac{1}{\left.\mid...
If the book had said that electrical potential energy is the negative of work done by electrical force on a charge, then the definition would be very clear and easy to understand. So, why should the book give this confusing definition instead.
Here is my solution, which is correct.
The tilt of the water at the top can be described in terms of ##x## and ##y## as ##y = \frac{2y_0}{L}x##. The height of the water at any given x is then equal to ##h + \frac{2y_0}{L}x## where ##x \in [-\frac{L}{2}, \frac{L}{2}]##.
So the potential...
It is my second "energy state diagram problem" and I would want to know if I am thinking correctly.
First I have done some function analysis to get a glimpse of the plot:
- no roots but ##\lim\limits_{x\to-\infty}U(x)=\lim\limits_{x\to+\infty}U(x)=0##
- y interception: ##U(0)=-U_0##
- even...
There is a formula for the potential ##\varphi## outside of a homogenous ellipsoid of density ##\mu## in Landau\begin{align*}
\varphi = -\pi \mu abck \int_{\xi}^{\infty} \left(1- \dfrac{x^2}{a^2 + s} + \dfrac{y^2}{b^2 + s} + \dfrac{z^2}{c^2+s} \right) \frac{ds}{R_s} \ \ \ (1)
\end{align*}where...
What do we think re the most powerful sci-fi weapons are that we could realistically envision becoming reality one day. I am wondering if we will ever be able to build anything more powerful than matter / anti-matter explosions like Star Trek's Torpedo's.
In orbital mechanics, the effective potential is given by ##\frac {1} {2} m r^2 w^2##, which can be expressed in terms of angular momentum ##L## which is conserved.
Yet, https://web.njit.edu/~gary/321/Lecture17.html apparently shows the centrifugal potential as the negative of the above...
Good afternoon to everybody. I have may be a stupid question according to the tangential part of the electric field near the surface of the conductor. Why is it zero? The normal part is zero on the distance of Debye cause of screening. But is this situation the same for horizontal direction...
Hello,
I'm seriously confused on several things around how concretely
batteries create potential difference in order to force the electrons
circulate trought the circuit wire.
Almost all explanations I found (wikipedia, diverse tutorials, intro scripts, etc.) explain it in nearly
the same...
I have tried to solve the problem through the use of a rotating reference frame, since I should have as a solution an orbit given by the Kepler potential, but I haven't come up with anything. Any ideas ?
Good evening,
I got a seriously problem at understanding the membrane potential for ions in a cell. Particulary, i don't understand the case for example for ions with a charge of 2 or higher. I take a look on two scenarios: If you got an ion like calium and got a concentration ratio of 1:10...
Hello there. Do you know any paper that derive the Lennard Jones potential ##V = \epsilon [(\delta / r)^{12}-2(\delta / r)^6]## theorically? If you know a book instead, let me know. Thank you
I understand that potential energies are energies relative to reference points. For example, gravitational/electrical potential energy is relative to a point at infinity. What is the reference point for centrifugal potential energies?
In the case of planetary orbits, must the reference point...
The equation below allows us to calculate the potential energy of a continuous distribution of electric charge.
$$U=\frac {\epsilon_0} 2 \iiint\limits_\text{Entire electric field}\vec E^2\,dV$$
In my textbook, the author states
$$U=\frac 1 {8\pi\epsilon_0}\iiint\limits_\text{Entire electric...