All Questions
17
questions
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2
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128
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I am confused about the minus signs in potential and kinetic energies
For a basic problem consisting of a ball on a loaded spring that shoots into the air I get the following energy balance:
Then I get for a point of the ball in the air:
$$\Delta KE= W = - \Delta PE.$$
...
- 2,035
2
votes
3
answers
3k
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Does everything have potential energy? + Question about mechanical energy
I'm currently learning about potential energy, kinetic energy, and mechanical energy, and I have a few questions:
Does everything have potential energy? If yes, how so? For example, does a book ...
0
votes
0
answers
231
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What does negative value for potential energy mean?
What does negative value for potential energy mean and which is more stable in potential energy for example -3000 or -4000? I read that it doesn't mean anything and the values of the energies are ...
- 109
1
vote
1
answer
674
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Reference Point for Potential Energy
The title is quite misleading, sorry for that i couldn't think of any other title.
Energy is a certain quantity whose value is constant anywhere in space. There are different forms of energy such as ...
0
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4
answers
1k
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If Gravitational potential energy increase with height then why it is 0 at infinity?
Due to MGH relation, if we increase height then potential energy increases. Then why it is zero at infinity?
1
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3
answers
4k
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$\Delta K=\Delta U$ vs $\Delta K = -\Delta U$
While doing physics homework, I noticed that in some problems, the change in kinetic energy(KE) is equal to the change in potential energy(PE), even though I learned that conservation of energy shows ...
0
votes
2
answers
296
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Sign in $\Delta U= -\int\vec{F}\cdot d\vec{l}$
So I have been trying to understand why there is a negative sign in the following$\Delta U= -\int\vec{F}\cdot d\vec{l}$
I wanted to try to understand it by trying to derive the gravitational ...
- 157
0
votes
1
answer
205
views
What exactly makes negative energy negative?
Antimatter is the opposite of matter since it has opposite electric charge (e.g. proton -> positive whilst anti-proton -> negative).
So what exactly makes negative energy negative? What property does ...
1
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3
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2k
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Work kinetic energy theorem
I don't understand the wordings of this theorem. Can someone please help me in understanding this? Secondly, on what basis are the sign conventions in this theorem applied? I get confused in positive ...
- 39
4
votes
3
answers
3k
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Relative potential energy vs Absolute potential energy
I have seen in many textbooks and sources which say that we can't experimentally measure potential energy but we can measure differences in potential energy.
$$\Delta U_g=-W_g$$
Choosing zero ...
- 181
8
votes
7
answers
3k
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Does energy have a sign? [duplicate]
Quantities like position and time allow us to place our origin anywhere, but can the same be said for energy? I was thinking about the way we have defined the quantity gravitational potential, and for ...
user154527
-1
votes
1
answer
71
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How can negative total energy mean a bound state is potential zero is arbitrary?
My Understanding is that if the Hamiltonian (H) plus potential (V) of a particle if negative than we have a bound state. However I also know that a potential is defined by placing a zero at an ...
- 41
0
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1
answer
607
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Linking the work-energy principle with potential energy in the context of gravitational fields
I am trying to derive the equation for gravitational potential energy $E=-GMm/r$. On the Wikipedia page for energy:
https://en.wikipedia.org/wiki/Work_(physics)#Work-energy_principle it says that $W=-...
1
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2
answers
2k
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Gravitational Potential Energy and Zero Points
I have two questions.
1) The first one has to do with the formula for deriving Gravitational Potential Energy. I learned that, for the derivation of Gravitational Potential Energy given large ...
- 3,200
1
vote
3
answers
463
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What exactly does voltage refer to?
Considering a charge moving down a wire, the electric field does work on the charges. The work done by the electric field can have two outcomes: it can increase the kinetic energy of the charge ...
- 3,997