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0
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0answers
38 views

Photon Energy and Einstein Equation $E=mc^2$ [duplicate]

If the mass of a photon is zero and these ones travel to the light speed, how may I explain Einstein's equation $E=mc^2$? It is well known that the energy associated to a photon may be calculated ...
4
votes
2answers
113 views

Is the Einstein Energy-Momentum equation $E^2 = p^2c^2 + m_0^2c^4$ valid only for Free Particles?

Is the energy -momentum relation $$E^2 = p^2c^2 + m_0^2c^4$$ satisfied only by free particles or even bound particles? Does the Energy refer to total Energy(including potential) or only (kinetic ...
11
votes
3answers
2k views

When an atom is split, what form of energy is released?

When an atom is split, what form of energy is released? All of the websites I have looked at say there is a lot of energy released when an atom is split, but it never says what form of energy it is ...
5
votes
1answer
492 views

Why does the electron volt seem inconsistent with mass?

If I understand correctly, an electron volt is the work done when an electron is moved from a plate with a voltage of 0V to another plate with a voltage of +1V. This is represented by $V = W/Q$, or $W ...
1
vote
2answers
39 views

Can change in temperature cause a change in mass of an object?

If a gold bar is heated to say 200 degree Celsius then will it have the same mass at say 10 degree Celsius. Does energy has mass? If so then does this increased 'heat energy' cause an increase in the ...
2
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3answers
38 views

Stability of nuclides in regard to the forces acting upon its nucleus

I am having trouble piecing together some information regarding the stability of a nucleus. I have read that iron-56 is the most stable isotope, because it has the highest binding energy per nucleon ...
1
vote
4answers
213 views

Coupling fission and fusion and disappear all mass. Why doesn't this happen?

I'm confused about the fact that in a fission process the masses of the "products" are less than the mass of the "reactants". And in a fusion process the masses of the "products" are less than the ...
-4
votes
2answers
52 views

Do photons have/contribute to mass?

Do electrons gain mass by absorbing photons during excitation and releasing them by returning to the ground state? Do photons have mass in the form of energy by $E=mc^2$?
1
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2answers
60 views

Can we create heavier particles with high energy?

It is known that an electron and a positron are created from the energy of gamma ray, is it possible to create heavier particles like proton and neutron from the energy of gamma ray? (if so what is ...
3
votes
1answer
141 views

Where does this relation between gamma, energy and mass come from?

I am doing a course that has used this relation a few times now: \begin{equation} \gamma = \frac{E}{mc^2} \end{equation} It makes sense physically, when $E = mc^2$ the particle is at rest and ...
0
votes
5answers
131 views

Can dark matter be converted to dark energy?

According to energy mass conversion law, mass can be converted to energy. So is it possible to convert dark matter into dark energy?
1
vote
2answers
96 views

Why doesn't Beta Decay violate the laws of physics?

In Beta decay, a neutron decays into a proton, and "throws out" an electron at high speed. However, this, to me, suggests that the law of conservation of mass is not being kept here. Neutrons have a ...
0
votes
1answer
32 views

Mass-energy-equivalence's effect on SI units?

Maybe I'm misunderstanding mass energy equivalence, but can we use it to get rid of the Joule (or the kilogram) and have a single unit for both? It seems weird that if they're equivalent they'd have ...
2
votes
3answers
66 views

Does (mass $\rightarrow$ pure energy) conversion need both matter $and$ antimatter?

A question in my revision guide: "Explain why the mass of a tree cannot be converted directly into energy." The answer explains that the tree contains particles but not their corresponding ...
0
votes
2answers
73 views

How does electron gets negative charge and proton gets positive charge? [duplicate]

I researched much in physics but I still do not know how does electron gets negative charge and proton gets positive charge? What is the source of this charge and energy? How can this particles ...
4
votes
4answers
207 views

How to derive $E=mc^{2}$?

Is there some way to derive $E=mc^{2}$? I can understand that energy in something is proportional to its mass, but the $c^{2}$ part. I have no idea. It seems like the way the units are going it would ...
21
votes
2answers
5k views

Why can't I do this to get infinite energy?

I know that I cannot do this because of conservation of energy, so I am looking for an answer as to why this will not work. So by my understanding of Einstein's whole famous $E=mc^2$ thing it is ...
0
votes
2answers
34 views

Does Energy have a similar effect on time as Mass would when considering the gravitational field both exert?

I was thinking about light and the different frequencies. The higher the frequency the more energetic the photon. The higher frequency photon being more energetic seems counterintuitive when ...
0
votes
2answers
43 views

Semi-empirical mass formula

The mass formula is given by $M(Z,A) = ZM_{p}+(A-Z)M_{n}-a_{1}A+a_{2}A^\frac{2}{3}+a_{3}\frac{Z(Z-1)}{A^\frac{1}{3}}+a_{4}\frac{(Z-A/2)^2}{A}+a_{5}A^\frac{-1}{2}$ So I am just wondering here what ...
0
votes
1answer
28 views

Mass of an Atom

So the mass deficit of an atom, denoted by $\Delta M(Z,A)$, is given by the following formula, $\Delta M(Z,A) = M(Z,A) - Z(M_{p} + m_{e}) -NM_{n}$ However since the rest mass of an electron is a lot ...
1
vote
2answers
40 views

Binding Energy of an atom

I would like to know if there is any difference between the binding energy of a nucleus and the binding energy of an atom and what exactly do we mean when we say Binding energy per nucleon.. Edit to ...
0
votes
1answer
79 views

How can electromagnetic waves be affected by gravity if photons have no mass? [duplicate]

I have found answers that say that gravity interferes with the oscillating electric and magnetic fields of the waves and others that say that since gravity is a bend in space-time, in which case the ...
0
votes
1answer
125 views

If you heat a closed tube, does its mass change?

This is a result of a debate with friends. We were more concerned with the nano- and smaller-scale effects than the larger effects. Let's assume that we have a closed tube filled with air. We weigh ...
0
votes
0answers
52 views

What is the difference between mass defect and mass deficit?

Is there any difference between the mass defect and the mass deficit? I have read that the mass defect of a nuclide is never negative and have also been told that the mass defect is the same as the ...
0
votes
5answers
207 views

What is the significance of the “squared” in $E =mc^2$? [duplicate]

If $c$ is just an arbitrary constant, why don't we say $E=mc$ and define the value of $c$ to be $\sqrt{299 792 458} \approx 17314$ meters per second? Or, why not use $E=mc^3$?
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votes
3answers
1k views

Could any object have zero mass? [duplicate]

Energy and mass are interrelated. As everything has energy could any object be massless? For example a photon is a packet of energy but still it is considered to be a massless particle. Why is it so?
0
votes
2answers
77 views

Are black holes an infinite source of energy? [duplicate]

Black holes are considered particularities because in a determined point in time they are pointless, as consequence there are some mass in a null space so the density become infinite. Finally if ...
0
votes
2answers
67 views

The semi-empirical formula and $E=mc^2$

The semi-empirical formula is used to find the binding energy of a nucleus. But if you know the mass of a nucleus and the number of neutrons and protons that this nucleus consists of (and you know ...
-5
votes
2answers
120 views

Einstein's mass-energy equivalence [closed]

Einstein's wonder equation $E=m c^2$,if we take energy is proportional to the mass, we can put single constant to make that equivalent equation. We all know that ...
0
votes
1answer
91 views

Where does mass go when energy is converted in to photons?

If matter and anti-matter annihilate each other they emit a photon with the energy that corresponds to the mass, right? This is the best example I could think of matter/energy being converted directly ...
2
votes
1answer
276 views

Will a hot object have more gravity than a cold object?

Imagine two objects, identical and having the same mass. Now my question is, if you heat one object and do not do anything with the other object, will the hot object possess more gravity (because it ...
2
votes
2answers
56 views

The mass/energy of an $H$-atom and the gravitational force between it and another particle of mass $m$

The gravitational force between an $H$-atom and another particle of mass $m$ will be given by Newton's law: $$F=\frac{GMm}{r^2}$$ The question is, what is $M$ here? I thought the answer would be ...
0
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0answers
20 views

How to define the parameter $\beta_{CM}$ of the transformation of pseudorapidity of the referencial LAB to CM

How can I determine $\beta_{CM}$ knowing the energy of the center of mass (CM), and without knowing anything about the particle mass? I have only information about the pseudorapidity in the ...
2
votes
1answer
115 views

Can energy bend space? [duplicate]

I know mass bends the space around it and I also remember matter can be converted into energy and vice versa, so my question is: can energy interact with space in a similar fashion as matter does?
0
votes
2answers
70 views

Is there any gravitational force between two stationary neutrinos, a billion light years apart?

Gravity is supposed to act over an infinite distance. But if the force is very weak (due to low masses) and the distance is very far, is the force actually 0? Or is the force so low that it is ...
0
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4answers
260 views

Mass, energy, and entropy.

I have a seemingly simple question about the relation between these three that for some reason doesn't make sense to me. If entropy is the disorder of a system, then a low entropy state is one of ...
1
vote
1answer
95 views

Laws of physics in curved space-time

The speed of light is not constant everywhere in a gravitational field. Suppose there is a region of space-time which is curved due to gravity such that the speed of light or any electromagnetic ...
-1
votes
2answers
119 views

Does matter become energy at the speed of light? [closed]

According to modern physics, we can't push matter to the speed of light. It would slow down (relative to its environment). But theoretically, if matter were to travel the speed of light, would it ...
-2
votes
2answers
58 views

How fast does an object have to be going to turn into energy [closed]

Albert Einstein's equation, $E=mc^2$, says that an object has to be going at the speed of light squared to turn into energy. How fast would this be in miles per hour?
1
vote
1answer
68 views

Is it correct that whenever energy change, mass also change?

Can I simply claim that, according to the mass-energy equation $E=mc^2$, whenever the energy of an physical object (not necessarily a microcosmic one) changes, its mass also change? Okay, I ...
3
votes
3answers
136 views

How is it possible for the wavelength of light to change in a medium?

So my physics class has just finished a long unit on optics while at the same time I've been trying to teach myself relativity. I admit my understanding is probably rudimentary, but I figured all the ...
-4
votes
2answers
143 views

$? = mc^{1.9}$ makes me crazy [closed]

If energy equals mass times the speed of light squared, what is mass times just under the speed of light? It's not energy,,,yet. Michio Kaku said in a physics video that the faster mass goes, the ...
3
votes
2answers
113 views

What would be the photon's effective mass in Newton's Law of Gravitation?

If we equalize the force from the Newton's Law of Gravitation to Force on a photon in a gravitional field (I don't know if there is an equation for it). What would be the photon's effective mass? (I ...
0
votes
1answer
52 views

Why photons are having energy when they are massless? [duplicate]

As per the Einstein equation $E=mc^2$, the energy of the particle is depends on the mass of the particle. Or else in other terms the energy is proportional to the mass. If the photons are having zero ...
2
votes
3answers
529 views

How much energy is needed to create an electron?

I know how to calculate the electrostatic energy of a sphere (it has a well defined radius). But how can I calculate the electrostatic energy of an electron as it is a point particle? By electrostatic ...
6
votes
9answers
459 views

Why does my apple not weigh 500 tons?

Related to this question: What is potential energy truly? $E=mc^2$ - energy equals mass. So, if an object has gravitational potential energy relative to another object, it should have additional mass ...
4
votes
1answer
134 views

What specifically is incorrect about the Dirac Sea interpretation?

So taking the square root of $E^2 = (m_oc^2)^2 + p^2c^2$ yields two solutions. The Dirac Sea treats the negative solution as an infinite space of electrons with negative energy. All the observable ...
3
votes
4answers
406 views

Mass in special relativity?

Is the mass of a object at rest defined by $$E=mc^2$$ where $m$ is the rest mass. I.e. does the rest mass include every thing from thermal to gravitational potential energy and every other possible ...
3
votes
3answers
487 views

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 ...
2
votes
3answers
242 views

The mas-energy equivalence for rest mass

It is clear that the kinetic energy can be derived as $(m-m_0)c^2$. However, why do we say that $m_0c^2$ is the rest mass energy? It seems that this mass-energy equivalence for rest mass is just a ...