Questions tagged [mass-energy]

The special-relativistic relation connecting energy with mass, $E^2 - (m c^2)^2= (pc)^2$. May be used to provide accounting constraints in energy and momentum, both conserved in total, even in reactions where $m$ is not.

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How was mass increase measured? [closed]

Wiki (https://en.wikipedia.org/wiki/Electromagnetic_mass) says that: Thomson (1893) noticed that electromagnetic momentum and energy of charged bodies, and therefore their masses, depend on the speed ...
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Converting between mass and binding energy in semi-empirical mass formula

The semi-empirical mass formula is given in terms of the binding energy as: $$B(Z,N) = aA - bA^{\frac{2}{3}} - s \frac{(N-Z)^{2}}{A} - d \frac{Z^2}{A^{\frac{1}{3}}} - \frac{\delta}{A^{\frac{1}{2}}}$$ ...
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How weak are the Van der Waals bonds? What is their contribution to the total mass of an object?

We know that every binding energy can be expressed as a negative mass contribution to the total mass of the system. It is well known, for example, that composite nuclei have a “mass defect” when ...
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Why is internal energy of nucleons ∝ to binding energy? [duplicate]

In fusion , as two light nuclei fuse , the relative binding energy experienced by each nucleon is increased and hence the internal energy of the nucleons is decreased which by E=mc² causes a decrease ...
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Nuclear binding and internal energy [duplicate]

A section of some article: When you cool a body at rest its internal energy decreases. Since energy is related to mass, here $E=m_0c^2$, where $m_0$ is the rest mass, the rest mass of the body ...
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Strong nuclear force in fusion

I have read that there is an increase in the amount of the binding energy from the reactant nuclei and the product nucleus during nuclear fusion and this causes the decrease the internal energy (...
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Does a spinning disk weigh more than when it is stationary?

Relativity tells us that mass increases with velocity, does this mean the faster a disk spins the more it will weigh? If so, is this measurable with current technology?
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Conversion of mass into energy [duplicate]

If mass can be converted into energy , then doesn't it violate law of conservation of energy because one form of energy can be produced from another form of energy . But here in this case energy is ...
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Energy of particle in equilibrium

Suppose I have a mass let say a mass of M kg Imagine, it is in equilibrium No force is acting on it Due to no force its energy must be zero . But why it is said that mass at rest also has energy ...
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Does the mass in $E=mc^2$ change with the speed of the mass? [duplicate]

I was involved in a discussion on Quora about going faster than the speed of light and I pointed out that $E=mc^2$ implies that the faster the mass goes the more energy you would obtain from it. One ...
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Why is energy released when nucleons come together to form a nucleus?

Binding energy is defined as the energy required to split a given nucleus into it's individual protons and neutrons. But why when nucleons are combined they release energy? What is the origin of this ...
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Why can we consider the rest mass of photon is zero?

Because a photon has a momentum, we can calculate the relativistic mass of it according to the special relativity. Also according to this theory, the relativistic mass is proportional to the rest mass ...
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Momentum and Kinetic energy from a decay of single particle at rest into 2 particles

How can I find the kinectic energy $KE_n = E_n - m_nc^2$ and the momentum $p_n = \frac{1}{c}\sqrt{E_n^2 - m_n^2c^4}$ From $E_n = (\frac{m_{\lambda}^2 + m_n^2 - m_p^2}{2m{_\lambda}})c^2$, which result ...
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Why there is no reaction Deuterium + Deuterium $=\rm {}^{4}He$?

Why there is no reaction like $D+D={}^{4}He$ specified here and in other places like this? Apparently $2\times2.0141-4.0026=0.0256$ is positive. What is the problem with this reaction?
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Potential energy, mass transformation in energy? and nuclear reactions?

Lost mass is converted into kinetic energy after nuclear reactions but what happens to potential energy? (in the case of a non isolated system) I don't know a lot of potential energy and in my idea it ...
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Why can't a mass be accelerated to the speed of light if its mass does not increase with speed? [duplicate]

My question is similar to this question (If rest mass does not change with $v$ then why is infinite energy required to accelerate an object to the speed of light?) except that my question 1. is not a ...
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In special relativity, is it true that mass is conserved and energy is conserved?

If so, it would seem to follow that a photon has mass, because an atom that emits a photon loses mass. If the photon has no mass, then the total mass will be less and mass will not have been conserved....
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Origin of Nuclear fusion energy

What causes the mass of the two reacting nuclei to convert to energy and if it is for a purpose then why is it released. What is the source for this cause (if there)?
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A situation where mass and energy are separately conserved?

I know that in a closed system mass+energy is always conserved. For example, in an exothermic reaction, some mass is converted to energy. Now, I'm looking for a situation where mass and energy are ...
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Have there been any studies on the mass/energy that thoughts produce? [closed]

I am very interested in the concept of energy and manifesting a desired reality (which is more so thought of as spiritual or metaphysical rather than scientific). However, I do believe there is a ...
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What is Energy? Like, seriously, what is it? [duplicate]

Here's a question that's been on my mind for quite some time now. What the actual hell is energy? Like, seriously. I understand real-life is nothing like fiction where characters and machines can ...
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Nuclear reaction: loss of mass or conservation of mass?

Certain particles come together to form a nucleus, this causes a certain amount of energy to be released in the form of photons, the mass of the nucleus is less than the sum of the masses of its ...
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Are neutrinos' velocities related to their energies? As they are with other particles?

I have read extensively about neutrino energies, including in the popular press, and yet velocities of the neutrinos themselves (not the detectors they 'run into' or the leptons they 'create' after ...
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What is the quantum mechanical explanation of the Mass–energy equivalence?

What is the quantum or particle explanation of the equivalence between mass and energy described by Einstein? What mechanisms ensure this equivalence?
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Thinking about singularities and the speed of light

I apologize that this takes so much explanation. From what I understand about the idea of the "singularity" in a black hole, it's not taken literally as Infinite mass in zero density or ...
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Thought experiment and $E=mc^2$

Suppose we have an indestructible box that doesn't let through any matter or radiation or whatever. In the box, there is matter which is evenly distributed (state A). The energy content of the box ...
Possible to destroy matter on a "human" scale (i.e. $\mathcal{O}(1m)$) using a proton?
A naive calculation suggests that a proton moving in a vacuum at $(1-10^{-38})c$ would have relativistic momentum equal to $\gamma mv \approxeq 2\mathrm{kgms^{-1}}$ if we say $m = 10^{-27}\mathrm{kg}$ ...