# Tagged Questions

The property of an object that determines how much it responds to a force in Newtonian mechanics, and how much it interacts with gravity in the Newtonian framework. Mass also refers to the intrinsic energy of a particle in particle physics.

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### Why only left-handed neutrinos have been observed yet?

This is what I understood (it may be wrong, so please correct me): since every particle is "divided" into a lefthand and a righthand partner, which is what guarantees the particles to have mass, and ...
0answers
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### Do relativistic frames imply different realities? [duplicate]

From Einstein's principle of relativity space-time and mass are relative to the frame from which they are being observed. Now would that mean a ball moving at the speed of light wrt to earth would ...
2answers
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### Confused about volume, density and mass, help!

I got into an argument with my friend, which cast confusion on my understanding of density and its relationship to volume. I'm hoping to get some clarity. The argument involved describing density in ...
1answer
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### How does Newton's third law work

This law states that to each action there is an opposite and equal reaction. and I understand that this is the law that Rocket thrusters are built on. they use the combustion of fuel to push out hot ...
1answer
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### Deriving a diffusion equation from a given mass flux density [closed]

I am given that the mass flux density $q$ of a substance in a medium obeys the following physical law. $$q=-D\frac{n^3}{n-n_0}\frac{\partial n}{\partial x}+nv,$$ where $n(x,t)$ is the ...
4answers
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### Theoretical Possibility of “Opposite” Gravitational Mass? [duplicate]

This is an unusual idea that I have been entertaining for some time, and I can't find anything about it online. However, it is so simple that someone must have conceived it before. First, I will ...
0answers
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### Is there a mechanism, analogous to the Higgs mechanism for mass, that gives particles their electric charge? [duplicate]

Or is charge a fundamental property?
0answers
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### Sudbery's Quantum Mechanics and the Particles of Nature, Chapter 1, Problem 2: Calculate the mass of the electron [closed]

I'm currently working on the problems for Chapter 1 of Quantum Mechanics and the Particles of Nature: An outline for mathematicians by Anthony Sudbery (Cambridge University Press, 1986; reprinted (...
1answer
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### Neutrinos are slower than gravitational waves according to their mass?

Neutrino bursts are observed before the visible light of supernovas, most famously SN 1987A. Astronomers likewise expect gravitational waves. Gravitational waves are supposed to travel at exactly the ...
0answers
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### If mass increases as velocity increases, does gravity increase as well? [duplicate]

The way I understand it, velocity and mass are tied together with relativity. As I increase in velocity, I increase my mass until my mass is so great that it would take more energy than the entire ...
2answers
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### Top quark mass $m_t$ at energy scales $\mu < m_t$?

Edit - Maybe formulated differently: Does it make sense to talk about the top mass at energies below $m_t$, although in all processes the corresponding energy scale is above $m_t$, because of the rest ...
0answers
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### Applications on Newtons' laws [closed]

A light string passes over a smooth pulley and carries at one of its ends a body of mass 90 grams and it carries a body of mass 50 grams at its other end.the system started its motion from rest when ...
4answers
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1answer
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### first and second moments of mass

why is the second moment of mass used as moment of inertia, and why is the first moment of mass about an axis not used as moment of inertia? i understand that first moment is product of mass and its ...
1answer
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### How do I calculate the moment of inertia with velocity? [closed]

How do I calculate a total moment of inertia when I have point mass with velocity? It looks like this: If I understand correctly, firstly I have to find a center of mass. What do I do next?
1answer
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### Why is the top quark mass reconstructed too high when the bottom quarks were swapped (semileptonic decay of a ttbar pair)?

I use a dataset containing simulated events of semileptonic $t\bar{t}$ decays ($t\bar{t} \rightarrow W⁺b W⁻ \bar{b} \rightarrow q\bar{q}bl\nu_l\bar{b}$) at CMS, LHC. For each event, the four-momenta ...
0answers
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### Why does mass attract? [duplicate]

Question stands as title says: Do we know (straight probable is reasoning is meant by "knowing") why mass is doing so?
3answers
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### Is mass directly or inversely proportional to time? [closed]

From a Newtonian perspective: F = ma F dx = ma dx E = m (dv/dt) dx m = (E dt) / (dv dx) Mass is directly proportional to time, if time slows down then mass goes down or decreases. From a ...
2answers
105 views

### What happens during mass-energy conversion?

A mass is another form of energy. When a mass ceases to exist as 'matter', it exists as energy - in the forms of energy we generally know (light, heat). But is this so simple? When a mass exists in ...
1answer
147 views

### How to measure the mass of the lower part of a human body?

An Olympic weightlifter asked me this question and it has been bugging me for a couple of days now. Suppose "lower part" is defined as anything below and including the hip. This means that the ...
1answer
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### Spin of a gauge field

I was wondering what is the simplest way to understand the reduction of the Wigner's little group from $SO(d-1)$ to $SO(d-2)$ when one considers massive and massless fields respectively (in a $d$ ...
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### Why doesn't the four-gluon vertex give mass to gluons?

We have a four-gluon vertex and a gluon vacuum condensate. Why doesn't this provide us with gluon masses, as in the NJL model where the condensate gives rise to an effective mass term?