All Questions
Tagged with potential-energy energy
69
questions
7
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Example in motivation for Lagrangian formalism
I started reading Quantum Field Theory for the Gifted Amateur by Lancaster & Blundell, and I have a conceptual question regarding their motivation of the Lagrangian formalism. They start by ...
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10
answers
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How is energy "stored in an electric field"?
My physics teacher told me the statement "The energy of a capacitor is stored in its electric field".
Now this confuses me a bit. I understand the energy of a capacitor as a result of the ...
- 492
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1
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Feynman Lectures: Why a non-reversible weight lifting machine cannot lift higher that a reversible one?
Consider weight-lifting machines—machines which have the property that they lift one weight by lowering another. Let us also make a hypothesis: that there is no such thing as perpetual motion with ...
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3
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Coincidence, purposeful definition, or something else in formulas for energy
In the small amount of physics that I have learned thus far, there seems to be a (possibly superficial pattern) that I have been wondering about.
The formula for the kinetic energy of a moving ...
8
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6
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Why is potential energy negative when orbiting in a gravitational field?
I had to do a problem, and part of it was to find the mechanical energy of satellite orbiting around mars, and I had all of the information I needed. I thought the total mechanical energy would be the ...
- 2,889
7
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2
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Lagrangian potential for Newtonian gravity
In the Wikipedia site for Lagrangian (field theory) the Lagrangian density for Newtonian gravity is given by
$${\cal L}(\mathbf{x},t) = \frac{1}{2}\rho(\mathbf{x},t)\mathbf{v}^2 -\rho(\mathbf{x},t) \...
- 105
6
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1
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Lower bound on energy is potential minimum
Suppose we have a particle of mass $m$ that is in an eigenstate $|\psi\rangle$ of the Hamiltonian $\hat{H}=\hat{T}+\hat{V}$, where $\hat{T}$ is the kinetic energy operator and $\hat{V}=V(\hat{r})$ is ...
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What is the energy of a single charge system?
I will try to limit the question in the case of the electric fields, but is something that applies also to the magnetic ones.
There are two ways to express the energy in a capacitor:
By Voltage : $U ...
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4
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4
answers
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Does work-energy theorem involve potentials?
According to khan academy,
"Net work done on an object equals the object’s change in kinetic energy. Also called the work-energy principle."
Now, here we see that there is no mention of '...
- 7,980
34
votes
5
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Heisenberg Uncertainty Principle Applied to an infinite square well
I appreciate the statement of Heisenberg's Uncertainty Principle. However, I am a bit confused as to how exactly it applies to the quantum mechanical situation of an infinite square well.
I understand ...
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Kinetic energy of the object, but Potential energy of the system: Why is it so?
Examples from Principles of Physics (by Walker,Resnick,Halliday) will say it better:
Let us throw a tomato upward. . .as the tomato rises, the work $\mathbf{W_g}$ done on the tomato by the ...
user36790
6
votes
1
answer
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Why doesn't the potential energy of any object equal 0
Consider a particle on the ground. This particle is raised by a force of magnitude $mg$ to a height $h$ above the ground. At this point, the work done on the particle by the force is $mgh$, which is ...
- 2,770
3
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2
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Can the mass of a hydrogen atom be calculated in a gauge-invariant way?
Please excuse the lengthy question. It involves an interesting controversy which has arisen in discussions on this site:
Energy/mass of Quantum Vacuum
Relative potential energy vs Absolute potential ...
- 51.7k
1
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4
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Potential energy and the work-energy theorem
So the title's a bit irrelevant. And I'm having a tough time thinking how to describe my doubt but I'll try my best. Apologies if it is vague, do let me know in the comments.
So I just finished ...
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Has $E=mc^2$ been experimentally verified for macroscopic objects with potential energy?
In relation to this question: What is potential energy truly?, I'm wondering if $E=mc^2$ has been experimentally verified to hold true for macroscopic objects with increased potential energy? I'm ...
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