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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Minimum and Maximum Speeds of a Mass

I understand that it is impossible for a object with rest mass to travel at C due to time limitations, I also understand that the speed of an object is calculated using a frame of reference but what ...
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1answer
28 views

Mass density of a cylinder increasing with the square of the radius

I’ve had to deal with a question like this on a test on friday and I just can’t get it out of my mind. I was supposed to calculate the moment of inertia of a cylinder with an inhomogenous yet ...
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35 views

What really is force? [duplicate]

I know the second law of Newton says $F=ma$ which seems to me the most fundamental expression of the force. In other words, force cannot exist without a "forced" one. It is somehow a "secondary" being,...
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60 views

What am I missing on my thougth expierement? [on hold]

Before I say my thought experiment I wanted to state that most of my knowledge on physics and such is from college books, and not from actual instruction. I arrived at this conclusion and realized I ...
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2answers
66 views

When Does Mass Matter? [on hold]

I have been trying to wrap my head around this idea for a month or so, and I am not really sure how mass plays into the velocity of a moving body. I have not taken physics in a while, but one thing I ...
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1answer
57 views

Can we work out how fast we are traveling by looking at our mass?

If we (the galaxy) were traveling close to the speed of light; relativity says we would need proportionally more energy to go faster. Given that relative to the cosmic microwave background, the Local ...
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1answer
105 views

Does the factor $k$ in Hooke's law change in special relativity? [on hold]

let's say an object is tied to a spring and it's oscillating. But this system is moving in 0.5c. Then, the period of this oscillation increases. But the problem is $k$. I think the $k$ increases ...
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45 views

Why isn't mass conservation counted among the laws of thermodynamics? [closed]

Is this purely a historical artifact, a consequence of how the original formulators of the three laws were thinking and experimenting at the time? Or is there a compelling scientific/logical reason ...
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2answers
73 views

SI Base Unit definition of mass - obsolete?

According to the formal definition of the SI Base unit of mass, the kilogram, it is stated that "The kilogram is the unit of mass; it is equal to the mass of the international prototype of the ...
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2answers
272 views

I know that free fall in vacuum is independent of mass. But what happens in air?

Pardon me if this sound somewhat trivial to some of the highly qualified users here. So I know two objects will fall at the same rate if they are in absolute vacuum, so what I'm assuming is that the ...
6
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1answer
85 views

Why neutrino is always left handed

Why all neutrinos are always left handed while all anti-neutrinos are right handed.
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1answer
104 views

Why not $\rho^{2}=T^{\mu\nu}T_{\mu\nu}$ as an effective mass density (squared ) in general relativity?

Why not $\rho^{2}=T^{\mu\nu}T_{\mu\nu}$ as an effective mass density (squared) in general relativity? It's covariant, and as far as I can tell is zero for any electromagnetic field tensor. \begin{...
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1answer
37 views

Maximum “size” of a galaxy

I am aware of upper limits to the mass of burning stars and neutron stars, beyond which they degenerate into neutron stars and black holes respectively. And also, if I understand it right, there is a ...
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3answers
44 views

Can we give particle with no mass, mass? [duplicate]

Is it possible to take a particle with no mass and give it mass. For example light? Or increase mass?
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18 views

Can someone please give some references on scattering in Proca theory?

Can someone please give some references on scattering in Proca theory? I am looking for scattering calculations with massive photons.
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1answer
37 views

How do the right-handed fermions acquire mass?

I am constructing a presentation on how elementary particles acquire mass via interaction with Higgs field. I asked this question previously in a different form and received the usual clap trap, so I ...
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0answers
7 views

most efficient set of weights with whole number mass to n-power for balancing unknown mass on vertex of regular triangle

I saw this qustion: http://puzzling.stackexchange.com/questions/186/whats-the-fewest-weights-you-need-to-balance-any-weight-from-1-to-40-pounds Suppose you want to create a set of weights so ...
29
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6answers
4k views

Does the speed of light in vacuum define the universal speed limit?

Is light the thing causing the universal speed limit to be $299\,792\,458\,\mathrm{m/s}$? So the universal speed limit would be different if light travelled faster or slower? Or, is $299\,792\,458\,\...
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1answer
25 views

Rocket Propulsion Equation: Meaning of Net Force

Upon deriving the rocket equation, my textbook (Giancoli) states that the meaning of the net force on the final equation is the net force on M. Note that $M$ and $dM$ are used as the rocket (without ...
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1answer
77 views

Showing $m_I = m_g$ follows from the equivalence principle

The inertial mass of an object is defined as its resistance to acceleration by $\vec{F}_{net} = m_I\vec{a}$. The gravitational mass of an object is defined as the scaling of the gravitational force an ...
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1answer
38 views

A silly, but confusing, question about the Inertia coeficient of second law and inertial mass

My question is about the inertia coefficient on second law. To be more specific I have doubts on the notation. 1) Some authors show that the force $F$ is proportional to mass $m$ times acceleration $...
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2answers
70 views

What exactly is the relationship between gravity and acceleration?

I know that one of Einstein's key steps towards General Relativity was the realization that gravity and acceleration were related. I understand the free-falling elevator analogy, but the relationship ...
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3answers
63 views

Weight loss of a flashlight due to light emission

I watched this video. At one point, the man explains how a flashlight loses some mass due to light emission when turned on. OK, I get that. Then he talks about a different situation, where the ...
29
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5answers
4k views

Do massless particles really exist? [duplicate]

I was in doubt, so I went to wikipedia. There it says "the photon has zero rest mass", but on the side description it says the mass is $<1.10^{-18} \:\mathrm{eV}/c^2$. So is the mass of the photon ...
3
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1answer
56 views

How did physicists conclude that 98% of mass is due to the strong force?

On a video on YouTube called 'weak and strong nuclear force (9/15)' at 0:55 a scientist said that 98% of mass is due to the strong force.
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3answers
102 views

What is the connection between inertial/gravitational mass and relativity?

In Einstein/Infield 's The Evolution of Physics (32-35) the authors establish that inertial mass and gravitational mass are the same and then connect this to relativity.Throughout these pages I was ...
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28 views

Effective mass vs. effective charge

In a semiconductor the effective mass multiplying the drift velocity is the result of the scattering of electrons off the ions in the crystal. I know that at least in the lowest order approximation ...
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1answer
48 views

Working out a specific charge of an atom?

I know how this formula work if the mass of the nucleus and the charge of the nucleus is given, however I do not understand how they get them as I have two books which do it differently. So the ...
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2answers
293 views

Atomic Weight and Time Dilation

So, this might sound kind of ridiculous but I was thinking about Relativity and since Gravity is a warping of Space-Time, or Time Dilation, why don't we measure Atomic Mass in Units of Time Dilation? ...
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1answer
38 views

How to determine the overturning moment on a stand alone, uncovered bean pole tipi

I will preface this by saying I am a highschool student who has not yet had a physics class. I engineered and built a hexagonal shaped, open bottomed, planter to hold soil that would contain pole ...
0
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1answer
84 views

Why is mass times position not used in physics? [closed]

The momentum $\vec{p}=m \vec{v}$ plays a very prominent role in physics. Why is the same not true for the quantity $\vec{q}=m \vec{r}$? E.g. one can write angular momentum as $\vec{L} = \vec{r} \...
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2answers
65 views

Interpretation of the mass of the field

Before QFT I had never thought if a field should or should not have any mass. Now it turns out that either case is possible. It might be naive to think this way, but I picture the mass of the field in ...
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1answer
36 views

Will Project Avogadro introduce a new constant? [closed]

Will the Avogadro Project introduce a new constant? It seems to me that the aim of the project is to define the kilogramme as some constant number of silicon atoms. What would this constant be ...
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4answers
126 views

If a photon has no mass why doesn't it have infinite speed? [duplicate]

Please help a naïve layperson understand -- if a photon has no mass, why is its velocity limited at all? Shouldn't a particle with no mass be able to travel at an infinite speed?
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2answers
115 views

Determining Mass of Spectroscopic Binaries

I know that the mass of a binary star system is given by Kepler's Law: $$\mathrm{m_1 + m_2 = \frac{4 \pi^2 r^3}{GT^2}}$$ Further we know that: $$\frac{r_2}{r_1} = \frac{v_2}{v_1} = \frac{m_1}{m_2}$$ ...
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1answer
51 views

Can light change the shape of a black hole?

If light orbits a black hole without ever getting closer or further from it, and the black hole pulls on the light from all directions nearly simultaneously, does the black hole extend at its equator? ...
8
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1answer
185 views

How does the Higgs field provide mass to the known elementary particles and does even thinking about amplitude and frequency have any bearing on it?

One of the first things I was looking for when I found this site was a clarification on what an increase of mass/energy is when Matt Strassler was using the analogy of tightening a spring and applying ...
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1answer
43 views

why do microscopic cracks happen?

2 weeks ago i asked a question about " Gas permeation through solid metal? " i have got a very good answer here .but microscopic crack was mentioned in the answer. i searched in Internet but i didnt ...
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2answers
67 views

How does rotation of a mass affect the geometry of space? [closed]

I understand (or rather, I have been told, but do not understand) that a large mass can distort space by its rotation. While I am somewhat familiar with the concept of a mass distorting space and ...
1
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0answers
44 views

Mass term in Maxwell's Lagragian for Electromagnetism

In the scalar field Lagrangian the mass term is given by $$m^2 \phi^2.$$ But the equivalent term in Maxwell's Lagrangian for electromagnetism is $$m^2A_{\mu}A^{\mu}.$$ But I don't know why the ...
2
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2answers
68 views

Difference between KE “relativistic” mass and heat mass

I have been told in several answers that the term "relativistic mass" is no longer considered adequate wrt. the mass/energy increase in KE. Yet, I read that 1 Kg of gold's mass ingreases by 10^-14 Kg ...
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3answers
100 views

What is meant by rest in rest-mass?

As far as I know only photons are considered to have no rest-mass. In common words when it doesn't move it 'disappears'. Electrons and quarks should have a rest-mass. But are they really at rest? ...
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2answers
75 views

The criteria of light

My question is regarding if the "speed of light" 299,792,458 m/s should only apply to certain frequencies of light/colors/amplitude and most the medium in which it travels at 299,792,458 m/s . Shouldn'...
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0answers
46 views

Why is Avogadro's constant not exactly the inverse of the atomic mass unit (kg)?

First, Avogadro's constant (in essence, but off in terms of decimal place) is the inverse of the atomic mass unit (kg). Why are the two constants off by 10^3? Look at the picture for a quick diagram ...
0
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3answers
85 views

Does the mass of a brick increase when you lift it? [duplicate]

If a person takes a brick, and lifts it to a height of 1 m, will the mass of the brick increase?
0
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1answer
35 views

Kaufmann's experiment 1902

Kaufmann's experiments (1902): http://en.wikipedia.org/wiki/Kaufmann%E2%80%93Bucherer%E2%80%93Neumann_experiments#Historical_context About charge to electromagnetic-mass ratio. Fig 2 has a plot of ...
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30 views

What is the relationship between an expanding universe, an increase in entropy and the the creation of mass?

What is the relationship between an expanding universe, an increase in entropy and the the creation of mass? Could the creation of mass be driven by or in equilibrium with the creation of space?
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3answers
68 views

Why do we need $SU(2)\times U(1)$ invariant mass terms if the symmetry will be broken anyway?

In the SM we can not add fermionic mass terms like $m \overline{e}_R e_L$ to the Lagrangian since these terms are not invariant under $SU(2)\times U(1)_Y$. After introducing the Higgs in the unitary ...
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2answers
191 views

Is it possible for the Higgs Field strength, to increase with time? [closed]

Magnetic fields are created when an electric current flows: the greater the current, the stronger the magnetic field. What influences could affect the Higgs Field? If the Higgs field grew in ...
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1answer
53 views

Are pure Dirac fermions (electrons, quarks, …) allowed to have effective Majorana mass?

Charged particles such as electrons and quarks are not allowed to have a hard Majorana mass (see here). With 'hard' I mean an explicit mass term in the Lagrangian which would break the corresponding ...