All Questions
16
questions with no upvoted or accepted answers
2
votes
0
answers
59
views
Are conservation of mass and conservation of energy *independent* constraints for physical systems?
I'm modeling fluid systems and want to use conservation of mass (aka 'continuity') and conservation of energy as constraints to help solve for certain system parameters. But it occurred to me that the ...
- 11.7k
1
vote
1
answer
85
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Does the intrinsic energy of an object vary, if measured at different heights in a gravity field?
The gravitational redshift has different interpretations. Several quantities vary with height (or seem to), by the same equation - time, energy, mass. I wondered if measurements can shed some light on ...
- 85
1
vote
0
answers
57
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Negative potential energy
In fusion of hydrogen into helium, hydrogen has negative potential energy which adds up and results in a mass defect..
Doubts:-
Why is there negative potential energy between the nucleons in a ...
- 21
1
vote
0
answers
82
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The relation between mass, inertia and energy
I have trouble understanding the following concept:
I learnt that mass is a measure of inertia, and that seemed logical enough. Yet separately I learnt that mass is a form of condensed energy. If ...
- 559
1
vote
0
answers
58
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An experiment about relativistic effect on weight
The draw explains everything. However I could not understand following:
At the right side, since 2 masses move, the total mechanical energy is bigger(since potentials are the same, and kinetic is ...
1
vote
0
answers
43
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Simulating Debris Burn Up Upon Atmospheric Reentry
For work I need to model Debris (1 gram to no more than 1000 km) burn-up upon reentry. I can't seem to find much information regarding this. I feel like I am looking for the wrong terms or something.
...
- 123
0
votes
0
answers
36
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Calculate Kinetic Energy of electron from effective mass?
The effective mass of an electron, due to special relativity, lower than the real mass. So I thought one can calculate from the mass ratio the velocity as it is dependent by a factor of $\sqrt{1-v^2/c^...
- 1
0
votes
1
answer
35
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Massive equivalent of a photon and deduction of a photon's linear momentum
Since photons have an energy given by $E=h\nu$, we could define a particle whose rest mass is such that it has the same energy than the photon: $E=m_0c^2 \Longrightarrow m_0=\frac{h\nu}{c^2}$. We now ...
- 1,616
0
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answers
27
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Tightly bound energy configuration for nucleons?
In fusion, why are nucleons of the product nucleus tightly bound and in a lower energy configuration than the nucleons in the reactant nuclei? I think the reason a large amount of energy is released ...
0
votes
0
answers
57
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What is the exact ratio of dark energy to mass?
I need to know the exact ratio between mass and dark energy (total dark energy in the universe / total mass in the universe). I could only find it to 2 decimal points (0.68). I need this to make this ...
0
votes
0
answers
39
views
Nuclear FISSION origin
Neutrons and protons consist of quarks, and when a neutron and a proton are squeezed tightly enough together, the quarks in each begin to interact and cause them to attract one another. The resulting ...
0
votes
1
answer
98
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How can the products of a higher energy fusion reaction be heavier?
I was told the mass defect of an atom is the difference in mass of the atom versus it's particles, for example:
carbon 12 is less massive than 6 protons + 6 neutrons + 6 electrons.
this negative ...
- 21
0
votes
1
answer
71
views
Energy and momentum
Does a muon or an electron with the same energy have the higher momentum?
According to $E^2=m^2+p^2$ if you increase the restmass, the momentum must decrease.
But if we look at a nonrelativistic case:...
- 109
0
votes
0
answers
92
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Derivation for relationship between rest mass, kinetic energy and momentum
I am trying to find a particle's rest mass in terms of its kinetic energy and momentum. Is this following derivation correct?
$(E_{0}+K)^2=E_{0}^2+(pc)^2$
$2E_{0}K=p^2c^2-K^2$
$2m_{0}c^2K=p^2c^2-K^...
- 155
0
votes
1
answer
107
views
Minimum energy of proton converting into a neutron
I'm given the isotope sodium 22 (which is positron emitter) and I'm stuck with calculating the minimum energy that a proton needs to convert into a neutron and a positron.
It got to do with $E=MC^2$ ...
- 1