All Questions
23
questions
-6
votes
1
answer
163
views
If a 100,000 ton container ship slams into a bridge at 8.6 knots how much energy was moved into the pylon and at what rate of transfer speed? [closed]
Edit: the entire question is in the title, the answer should be an amount of energy and a value of energy transfer in some unit, but not knowing enough about physics I don’t know what the appropriate ...
- 105
0
votes
1
answer
69
views
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 ...
- 278
2
votes
4
answers
405
views
Mass-energy equivalence and gravitational potential energy
If mass and energy are equivalent, and if gravitational potential energy is energy, why doesn't an object have more mass when it is at a higher altitude? Does the mass-energy equivalence work for ...
- 181
0
votes
2
answers
91
views
How can we say potential or chemical energy is part of an object?
I'm posing this question primarily in the context of special relativity. Also, I'd like to leave gravitational potential energy out of the picture since that would take us into a different direction ...
- 8,640
0
votes
1
answer
205
views
Energy released from destruction of an object [closed]
In the movie “Star Wars: A New Hope”, Luke Skywalker blows up the „Death Star‟. Assume
that the „Death Star‟ is a perfectly spherical spaceship with uniform mass distribution. The mass
of „Death Star‟ ...
- 3
0
votes
1
answer
57
views
What qualifies as “Energy” in the Einsteinian sense of the word?
As an absolute beginner to special relativity (and all the 1900s Einstein stuff), I find it hard to grasp the real meaning of the term energy used in the popular equations. I’ve heard it is possible ...
- 33
1
vote
3
answers
395
views
Relativistic energy of harmonic oscillator
What is the relativistic energy of an harmonic oscillator:
$$\frac{m_0 c^2}{\sqrt{(1-\frac{v^2}{c^2})}}+\frac{1}{2}kx^2$$
Or
$$\frac{{m_0 c^2}+\frac{1}{2}kx^2 }{\sqrt{(1-\frac{v^2}{c^2})}}$$
I think ...
- 199
0
votes
2
answers
143
views
Is $E=mc^2$ contradicting conservation of energy? [closed]
If we state that, on one hand, energy is conserved because :
$$\Delta PotentialEnergy+\Delta KineticEnergy=0 \tag{1}$$
And we state on the other hand that:
$$Energy=mc^2 \tag{2}$$
Don't we run ...
- 1,586
0
votes
1
answer
67
views
Is it, in general, better to speak of potential energy density or of energy density? [closed]
I read in this article:
Antimatter
And here we are: at the very end of the feasibility spectrum into the fantastic. Antimatter is made of antiparticles, which have the same mass as particles ...
1
vote
2
answers
102
views
What is the relativistic energy of a bounded static particle?
Premise: The speed of light is set $c = 1$.
Let's consider an electron in an external electromagnetic field. Its four-momentum will be
$$p^{\mu} = (E, \bar p) = (\gamma m_e, \gamma m_e \bar v),$$
...
0
votes
2
answers
1k
views
How can the total amount of energy in the universe be zero? [duplicate]
First of all, it is important to note that I'm not very savvy in neither general relativity nor any other area of expertise that answering this question may require. Therefore, I mean for the question ...
- 485
1
vote
1
answer
81
views
Mass-Energy equivalence in case of minimal coupling
The energy-momentum relation of a free particle is (in SI Units):
$$
m^2c^4 =- c^2 \vec{p}^2 + E^2
$$
Minimal coupling is a way to fix a gauge freedom for the choice of canonical momentum (which I ...
- 6,763
1
vote
1
answer
81
views
Where is the potential mass-energy located?
In general relativity, energy, including potential energy, creates mass. That accounts for things like the mass defect in atomic nuclei. But that potential mass-energy must also generate a ...
1
vote
1
answer
114
views
Is there any loss of potential energy during nuclear fission?
We know that energy is created during nuclear fission and there is a loss in mass. But every body possess potential energy even when it is at rest (where height = radius of earth). So during nuclear ...
- 111
14
votes
5
answers
8k
views
Does potential energy of an object increases its relativistic mass?
I know that in relativistic condition the increase in kinetic energy of an object increases its relativistic mass as $$m=\frac{m_0}{(1-v^2/c^2)^{1/2}},$$ and mass is another form of energy.
So my ...
- 141