Questions tagged [mass]
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. This tag does also cover effective mass.
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What's the speed limit for things with mass?
So the speed limit of the universe is 299 792 458 m/s, but only massless things like photons can archieve this speed. Since things that have mass can reach 99.99999...% speed of light, does that mean ...
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What contributes most to the mass of the proton?
i'm a bit confused about the origin of the mass of the proton (or other hadrons). It is said that it stems from the renormalization of the current quarks, which have about 1/100 of the mass of the ...
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${}$Higgs mechanism
Is is correct to say that, elementary particles have different masses, because they have different coupling strengths to Higgs field? And if yes. Does it make sense to question, why they have ...
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Has the mass of a proton been calculated from current quarks, through the renormalization process?
That's basically my question. Has the mass of the proton been calculated using QCD and the interactions between the current quarks? Perturbative methods obviously can't be used as they deal with ...
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Dark energy contributing to, or modifying, mass estimates?
I have found some papers (like this one: https://www.aanda.org/articles/aa/full_html/2009/45/aa12762-09/aa12762-09.html) which say that dark energy increases the potential energy in a system of a ...
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Calculate mass from time dilation
Hi not a physicist in any way so was wondering if I know the age (time passed) and mass of an one object and the age (time passed) of another object, can I calculate its mass?
So Object 1 is Earth:
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Weight distribution and support polygon
I was working on a problem of supporting an object with sticks and wondering about some use cases that would fail.
My approach is to place the n-sticks (for example 4) under an object with mass m ...
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Stueckelberg mechanism for interacting QFTs
The Stueckelberg mechanism or "trick" (see e.g. Section 4 of https://arxiv.org/abs/1105.3735) is basically a method to take the massless limit of massive gauge theories in a smooth way, ...
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Acceleration of centre of mass [closed]
In the solution to this question, they have first taken the component of downwards-acting gravity(g) along the incline which is the sin component then again they have taken the component of the gsin𝜃 ...
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Can someone explain 'virtual mass' in fluids in simple words (for a dummy/high schooler)?
so I recently came across the term 'virtual mass' and when I looked up more about it, it just gave me some stuff about fluid mechanics that I dont understand properly. My understanding of virtual mass ...
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Why do there exist negative and positive electric charges but only positive masses? [duplicate]
Why are there positive and negative charges but only positive masses? The spin-2 nature of gravitons is responsible for the fact that masses with the same sign attract, and the spin-1 nature of ...
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What weight does a scale show when you throw an object onto it?
Imagine you have a bucket (cross-sectional area $A$) on top of a scale. Into the bucket you begin to pour sand (density $\rho$) with a mass flow rate of $\dot{m}$. The total weight of the sand in the ...
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Neutrino Mass from Tritium
I just read: Researchers close in on the elusive neutrino (phys.org)
However, I think I'm missing something. The basic argument appears to be:
(decay process)
Tritium -> Helium-3 + β− (electron) +...
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What are the properties of an unknown object that guarantee that it has mass?
During JJ thomson experiment and similiar other experiments,they found that cathode rays were deflecting from its direction under magnetic fields and electric field,also the gold leaf attached to co-...
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Why adding weight to a motorcycle increases the stoppage distance?
I was doing my car license's questions, and it came up this question, why would the stoppage distance (the distance which the car stops after breaking) increase if you add more weight on top of the ...
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Mass energy equivalence of photons
It is said that elementary particles get their mass from the Higgs field. Also 99% of the mass of a proton comes from the strong force binding its quarks together. So we say that the mass energy ...
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Inertial Mass = Gravitational Mass. Why? [duplicate]
Okay, so the inertial mass of an object is always equal to the gravitational mass of the object. Conceptually, however, they seem different. Then what makes them identical? Is it because they are ...
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If positive mass distorts spacetime (spacetime gets curved toward the object) then would a theoretical negative mass make spacetime bulge out?
So lets assume for this question that negative mass exists then will a theoretical planet made of negative mass create an outward bulge in spacetime to create antigravity (repulsive). Also for this ...
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How is the energy content in 1 kg of water and petrol the same?
We know petrol is a fuel and water is not. But how come 1 kg of water and 1 kg of petrol have the same energy content? The total energy is given by $E=mc^2$, it says nothing about the chemical ...
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Why do we have momentum?
Momentum is the defined as the product of mass and velocity and can be thought as measuring how much motion something has. However, it is not clear to me why we need momentum and why force is not ...
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Why do my Milwaukee batteries weigh different amounts when charged vs uncharged
We use m12 small sized Milwaukee battery’s and I noticed when I use them I feel like they weigh different when using them sometimes while using them and then I read a article about batteries loosing ...
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Mass/Charge ratio of a black hole
Which order of mass/charge ratio must a black hole have to become overfed?
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What is the gravitational field intensity of a uniformly distributed mass content in Newtonian gravity?
In an infinite universe composed of single point masses which can be simplified as a uniformly distributed mass density, what is the equation for the gravitational field intensity in Newtonian gravity?...
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Why are gluons massless as their range is finite?
The range of electromagnetic waves and gravitational force is infinity and the particles exchanged during these interactions are photons and gravitons respectively. Both are massless following the ...
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What is the correct effective mass formula for an electron near a Brillouin zone edge?
In Kittle's Intro to Solid State physics Pg 197, it is stated that the effective mass of an electron near the lower edge of the conduction band is
$$\epsilon (K)= \epsilon_c +\frac{\hbar^2}{2m_{eff}}K^...
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Relative black hole [duplicate]
Let's suppose a nutron star(because it directly collapses into black hole afterwards) , if we move with velocity near speed of light than in our frame neutron star will also move with velocity near ...
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What exactly is kg? [closed]
Kilogram literally makes no sense. We say that we are 10 kilogram by using the weighing scale but according to its definition, it is the amount of matter contained in an object. So how much matter is ...
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How would you interpret the relativistic action, and how does the mass alter the action exactly? [duplicate]
How would you apply the lagrangian in special relativity? How do you interpret the expression?
The action is given by:
$$S=-mc^2 \int d\tau$$
where $m$ is the rest mass. If I understand correctly the ...
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Mass as generator of two distinct sets of phenomena
We know that mass, which is a continous parameter, generates two classes of different phenomena: the ones where $m=0$ and the ones with $m \neq 0$.
When a particle has $m=0$ we have phenomena which ...
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Triple Integral of Volume Concentration
I am working on a problem involving volume concentrations which are defined as:
$$ \phi_i=\frac{V_i}{V} $$
and are thus dimensionless. My problem is in $3$D and I have assumed that the components in ...
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Conservation of Hawking mass
Consider a spherically symmetric spacetime $M$ and define the (Hawking$^*$) mass through the equation $$1-\frac{2m}r=g^{ab}\partial_a\partial_b r.$$ I'm trying to prove that this implies
$$\partial_a ...
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Fermion mass correction always proportional to it's mass? even in case of mixing?
In QED, it is obvious that one-loop correction to the mass of the fermion ($\psi$) is proportional to its bare mass. However, it is not very clear to me whether it is general even in the case when ...
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How did the Higgs perturbatively give us the mass of all other particles?
In a recent conversation with my professor, he explained to me a misconception I had, in that given how physicists says that the Higgs "gives" the mass of all other particles, I was under ...
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Why is $F = ma$ at an instant, in variable mass systems? [duplicate]
While studying systems with varying mass, I have come across examples using thrust, and summing all the forces on the system including thrust, as being equal to $F_{net} = M\bar{a}$.
(My system's ...
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Can mass be defined using projective Hilbert space formalism instead of Hilbert space formalism?
The origin of mass in quantum mechanics was clarified by Bargmann in his famous paper, On Unitary Ray Representations of Continuous Groups (Annals of Mathematics, Second Series, Vol. 59, No. 1 (Jan., ...
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Why gold is always measured with a balance and not with a scale? [closed]
Why when trading gold apart of purity measurement its mass is always measured worldwide with a balance and not a scale?
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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^...
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2 Masses on a table confusion - Normal force and weight
Forces up are greater than forces down. However, the masses on the table obviously don't start flying upwards. Am I missing a force here?
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How and why bodies with great masses alter time?
I am dreadfully sorry for any mistake in jargon.
Theory of relativity, or so the interpretations of which I was merry to read; states that great masses get to alter, and this is where I get confused, '...
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Why is the least massive neutron star less massive than the most massive white dwarf?
Martinez et al. (2015) gives an example of a neutron star with mass as low as $1.17M_\odot$ (solar masses).
There is also the recent discovery of this candidate neutron star which is apparently only $...
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How come mass is conserved if the universe is formed from singularity? [duplicate]
If mass is conserved then how come there happened singularity?
since singularity is a point of infinite density and gravity.
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Why do electrically charged fields necessarily interact with Higgs field? [duplicate]
There are no elementary charged particles without mass. Since elementary particles appear to acquire mass by the Higgs mechanism, the above statement seems to imply that any charged particle must ...
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Is Dirac neutrino ruled out by current experimental observation?
I have read the neutrino mass problem. The unnatural smallness of neutrino mass implies the existence of new physics so the seesaw mechanism is introduced to solve this theoretical problem.
I ...
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Wald's derivation of Komar formula: passage on Eq. (11.2.5)
In Wald's General Relativity derivation of the Komar formula for the mass of a static, asymptotically flat spacetime there is the following passage:
Using Killing's equation $\nabla_a\xi_b = \nabla_{[...
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Why does gravity-induced quantum interference in quantum mechanics show that gravity is not purely geometric at the quantum level?
I am asking problem from the 'J.J. Sakurai and Jim J. Napolitano' Book Modern Quantum Mechanics 2nd edition. It reads as follows:
"...This experiment also shows that gravity is not purely ...
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How do the different Neutrino masses come about?
The determination of the Neutrino mass can be roughly divided in three strategies:
The neutrino mass from cosmological observations:
$$m_\nu = \sum_{i} m_i $$
The neutrino mass from the neutrinoless ...
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Why is there no uncertainty principle for mass or charge? [closed]
The uncertainty principle holds for pairs of certain observables, such as position and momentum.
All these observables have a relation to spacetime.
Other particle properties, by contrast, such as ...
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Has this random youtube crackpot trying to disprove GR inadvertedly stumbled on a genuine prediction of it? [duplicate]
I'm an Astrophysics major. I was watching strange fringe physics crackpots on Youtube to make fun of them, because I'm an acollierastro, planarwalk kinda gal. I came across this guy who thinks Black ...
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Differential expression for mass-out of a control volume
I am trying to express the rate of change of mass with respect to time out of a control volume. My control volume has dimensions $dV = dx\,dy\,dz$. For the mass-in change with respect to time I ...
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Does neutrino oscillation imply that the lightest neutrino has mass? [duplicate]
If my understanding is correct, neutrino oscillation only implies that the neutrino families have different masses. People usually infer from this that all the masses are non-zero, but we can only ...
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