Questions tagged [potential-energy]
Potential energy is the energy of a body or a system due to the position of the body or the arrangement of the particles of the system.
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Particle shot at a potential energy interface [closed]
A particle with velocity $v$ is shot at a certain angle towards a potential energy interface, where the potential energy is constant on both sides, but the potential energy on the opposite side is ...
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How does energy stay conserved if the force is time dependent and doesn't depend on location?
While reading The Theoretical Minimum for Classical Mechanics the author said that the derivative of the potential energy is equals the force and showed this equation describing the potential energy ...
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The electron potential energy of a single electron (in $H^+_2$ ) at any point
In my book it says:
We can choose a convenient reference by noting that the coulomb force at infinite distance is zero. It makes sense for this case, then, to choose $r=\inf$ as the vacuum level $E_v$...
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Does mechanical energy means total energy?
I know that mechanical energy is the sum of kinetic energy and potential energy. But there is a sentence in the book like this:
'Our primary goal, however, is to find the energies associated with ...
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Lagrangian, effective potential in a system without conservation of angular momentum [closed]
I've been struggling to understand how to derive the effective potential of a system.
I have a homework problem in which there are two bodies, $M$ and $m$, connected by a string with length $l$ such ...
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Model of Quintessential Inflation
I have a question about how the potential for an inflaton field is selected. It is clear that there are limitations associated with number of e-folds, scalar-to-tensor relation and scalar spectral ...
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Energy in electric field of an electron?
I am just trying to get an intuition for the Griffiths equation no. 2.45, where work done to establish a field E is given by
Say we want to solve it for electric field due to an electron (point-charge)...
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Effective Potential of Einstein Cluster
I was reading this paper (PDF), "On Einstein Clusters", and in equation (34) they write the effective potential of a particle moving in this system as $$V_{eff}(r)=e^{\nu/2}\sqrt{1+\frac{\...
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Why does the total gravitational potential in the universe exactly equal the total mass energy RIGHT NOW? [duplicate]
In the zero energy universe model, the gravitational field has negative energy, and this negative gravitational energy of all the distant mass exactly balances and cancels the positive mass-energy in ...
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Classification of equilibrium configurations for particles subject to elastic force constrained on a circle
I am interested in classifying all the possible equilibrium configurations for an arrangement of $l$ equal point particles $P_1, P_2, . . . , P_l$ $(l > 2)$ on a circle of radius $R$ and centre $O$....
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Change in Work-Energy Theorem
We have Work-Energy Theorem as follows:
$$W_c +W_{nc} + W_{ext} = ΔK$$ $-(1)$
, where $W_c$ = work done by conservative forces,
$W_{nc}$ = work done by non-conservative forces, $W_{ext}$ = work done ...
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Defintion of gravitational potential
I am not much clear regarding the defintion of "gravitational potential":
Is the work done for bringing the unit mass from infinity to that point by, gravitaional force or external force? (...
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Charge Distribution and Stability in a Conductive Solid Sphere
My friend came to me with a simple question: What is the charge distribution on a conductive solid sphere? Of course, I answered: 'Since the solid sphere is conductive, the electric potential would be ...
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When is the internal energy of a system not considered potential energy? [duplicate]
I have seen the total energy of a system, $E$, given in two forms:
$$E = K + U$$
where $K$ is the kinetic energy and $U$ is the potential energy, as well as
$$E = K + U + I$$
where $I$ is the internal ...
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About reference of potential energy
I have an exercise with a pendulum starting at horizontal position, then we give it a velocity of 5m/s pointing down, $z=0$ at this horizontal position and potential energy = 0. This confuses me ...
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Unbound States of the 1D Finite Potential Well [closed]
Edit: After writing a Python code to numerically solve the constraint problem on the coefficients with Gauss-Jordan elimination, it seems that the biggest problem was that I was treating the ...
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Potential energy of a spring formula [duplicate]
If a mass is attached to a spring(hanging from a wall) with spring constant $k$, causing an expansion $x$, then the potential energy stored by the spring is $\frac{1}{2}kx^2$. However, the potential ...
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Potential energy of an electric dipole without any external field
What is potential energy of an electric dipole without any external field?
If its 0 then why? Wouldn't the charges get attracted thus do work so they must have some potential energy.
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Some confusion regarding potential energy
We know that gravitational fields are attractive. Their direction is inward. So if we go from a nearer point to a farther point the potential energy should increase, and the work done should be ...
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Work and Energy Theorem - Theoretical Question
The work energy theorem states that for a given object
∆ Kinetic Energy = Work done by all forces ( Conservative, Non Conservative, External )
Here ,
Suppose if ∆KE = 0 , Potential energy has changed
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Direct conversion of potential energy into heat
Is it possible for potential energy to be dissipated (converted into heat) without being first converted into kinetic energy? Put differently, are there isolated systems at complete rest which turn ...
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Does infinite time dilation increase a photons energy to collapse to a black hole, and does it do the same for matter?
As I understand the mass of an object doesn't increase in a gravitational field according to general relativity. It just follows a geodesic, its worldline.
Now imagine a small marble falling straight ...
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Intermolecular force vs distance and energy plot
I have seen from the graph that Ea is increasing slowly while Fa is increasing really fast. On the other hand Er is increasing faster than Fr. My question is why ? Is there any mathematical idea ...
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What shape does a rope make when compressed / coiled up?
Let's say we have a rope placed on the line $y=0$ on a flat table in the $(x,y)$ plane. We place one hand on the rope at $x=0$ and $x=l$ and then move our hands together along the $x$-axis so that ...
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How do you calculate the potential elastic energy in only one of the springs of a series? What about if they were connected in paralel? [duplicate]
Given the elastic constants of 2 springs (k1=125N/m, k2=200N/m), how can you calculate the ratio between the potential elastic energy stored in the first spring (k1) when it is grouped in series with ...
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Effect of gravitational time dilation on a classic weighted pendulum clock versus a hybrid pendulum clock with a battery
A classical pendulum clock is powered by gravitational potential energy by weights. While a hybrid pendulum clock is somehow propelled by electric current. Both have the same pendulum swing as the ...
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Would it be right to say that “Electric Potential” = the potential energy of an individual unit of charge at a certain point in a electric field?
Any replies from people who actually understand the topic (better than me, to say the least lol) and are able to clarify the topic (unlike my teacher), are highly appreciated and encouraged.
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How Do Dielectrics Affect Electric Potential Energy in Capcitors?
I am currently learning about dielectrics and capacitors in my physics class and part of what I have learned is conflicting.
For starters the book says that capacitors do not interrupt current flow, ...
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Why is the electric field the strongest inside the resistors?
My understanding is that current is constant throughout the circuit. So it means that in the areas with high resistivity or small cross-sectional area the drift speed on electrons is the highest. ...
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Drawing a parallel between thermodynamic potentials and (mechanical) potential energy
Can we make an analogy, in the narrow sense, between potential (gravitational) energy and a thermodynamic potential (eg: free energy or Gibbs potential)? Specifically, if an object of mass $m$ is at ...
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Why is gravitational potential energy negative in this Lagrangian? [closed]
The question is given as follows:
From (6.109) shouldn't the Lagrangian be K(kinetic) - U(potential), but here its K + U? Unless the potential energy is negative, if so I'm struggling to come to ...
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Understanding effective potential energy
I am having troubles understanding whether $$\vec F=-\nabla U_{effective}$$ or $\vec F=-\nabla U$ with $$U_{eff}=U(r)+\frac{1}{2}\frac{L^2}{\mu r^2}$$ being $\mu=\frac{m_1 m_2}{m_1+m_2}$ the "...
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Why do things always want to reduce their energy? [duplicate]
Every object wants to reduce its potential energy, but why is that so? Does it have an explanation, or is it just a law we accept?
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Electric Potential and Potential Energy
Electric Potential definition is as follows:
Electric potential (also called the electric field potential,
potential drop, the electrostatic potential) is defined as the amount
of work energy needed ...
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Birds on power lines two feet versus one
So I know a bird can stand on a power line without being electrocuted because there is no current going to the ground. However, I know that curents will pass to different electric potentials. My ...
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Gravitational Potential Energy Behavior [duplicate]
I had a question regarding gravitational potential energy and escape velocity. I don't really understand the concept of escape velocity. I have been learning it as the velocity required for an object ...
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Derivation of the gravitation potential energy and gravitation potential
I have some slight confusing in deriving the gravitation potential energy.
In the image below, it explains that the gravitation potential energy is equal to the work done from infinity to a distance r ...
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What the physical interpretation of negative work done in case of attractive force? Also how negative potential energy is related with negative work?
I want to ask why potential energy becomes negative in attractive forces along with the work done. As the meaning of potential energy according to my knowledge is the amount of energy required to keep ...
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Angular or tangential term in gravitational potential energy change using polar coordinates
I was studying gravitational potential energy and tried to derive the potential energy change using polar coordinates.
$$\Delta U=-\int m \overrightarrow g (d \overrightarrow r)$$
Now, I thought that $...
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Interpretation of Equation of energy stored in continuous charge distribution [duplicate]
In the book "Introduction to Electrodynamics" by David J. Griffiths, $\boldsymbol\S$ 2.4.3$\blacksquare $ The Energy of a Continuous Charge Distribution, I came across this equation for ...
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Sign of work done by spring force [closed]
Two similar springs P and Q have spring constants $K_p$ and $K_q$ such
that $K_p>K_q$. They are stretched by the same amount. Compare the
work done by the springs. (NEET 2015)
$$W_p=-\frac{1}{2}...
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What is vector meson dominance and why is that related to QCD having a repulsive potential?
At long distances QCD is said to give rise to attractive force between nucleons by pion exchange and to give rise to repulsive force at short distance mediated by vector mesons. Is there a ...
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Efficiency of an oscillating system of springs in series
Suppose we have a system of two or more springs in series which support a mass. If the system is subject to an instantaneous longitudinal force causing the springs to oscillate, how does the ...
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Potential energy of a permanent magnet
A friend and I had a discussion about the potential energy of a permanent magnet, and we want to find out which of our views is right, but we can't seem to find information to confirm/disprove either ...
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Potential energy being converted into kinetic energy
It is said that the potential energy gets converted into kinetic energy for a freely falling body. But when a freely falling body comes to rest, that is, the velocity becomes 0, does the object still ...
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Calculating $C$ in $I_{CM} = CMR^2$
I am a bit new here, so please excuse any errors I might make.
I am a student in an AP Physics C: Mechanics course and I am conducting an experiment where I am experimentally calculating the C values ...
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On Potential Difference
We say that The work done on a coulomb of charge by the electric force from the terminals to move it from one point to another is called Voltage.Then my q is if I increase the length of the wire ...
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The lowering of a block using a spring and the net work done by each force involved
A spring hangs vertically in its relaxed state. A block of mass m is attached to the
spring, but the block is held in place so that the spring at first does not stretch. Now the hand holding the block ...
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If a car is *accelerating* uphill, does it *gain* kinetic energy?
I had an exam yesterday on physics (9th Grade), there was a question that confused me a lot. It said: "If a Gas Car is accelerating uphill, what happens to its G.P.E and K.E?"
A: It loses ...
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Why do we say that electric potential energy is stored in the electric field?
I have been learning electrostatics and came across capacitors. I don't really get why do we say energy is stored in electric field rather than in the charges upon which we or the battery does work. I ...