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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How can individual photons have different amounts of energy?

If photon is an elementary particle, how can different photons have different energy, if $E=mc^2$ and all photons have (or don't have) the same mass and the speed of photon is constant shouldn't it ...
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3answers
42 views

2 airplanes same size and shap different mass

2 identical balls of different mass dropped from same height reach the ground at the same time due to the acceleration of gravity being constant. If I understand correctly the ball with more mass ...
1
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2answers
38 views

Weight of mass falling through liquid

If I place a container of fluid on a scale and drop a non-buoyant mass into the fluid, will the scale read less as long as the mass is in motion downward as compared to when the mass is at rest on ...
2
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2answers
55 views

Mass, velocity and inertia [on hold]

If 5 ozs of weight is my engine, and this weight starts in the back of a four wheeled vehicle traveling down a decline gaining speed due to the engine mass to allow its inertia to carry it across a ...
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2answers
96 views

What is my real weight? [duplicate]

My weighting machines notes my weight to be 65. Should I read it 65N or 65kg. PS: I only need a correct comment. This question is different, since, I know very clearly what mass and weight are. But ...
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3answers
48 views

Conditions for the tension to vary in the rope

What are the conditions for the tension to vary in the rope. I have read below conditions 1. rope has to have some mass 2. rope is accelerating I get the 1st ...
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0answers
46 views

Is there anything that has mass but no charge?

Is there anything that has mass but no charge? I am of course aware of neutrons, but since these have internal structure and only a net non-zero charge, they will have a non-trivial electric field ...
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1answer
30 views

Does the shape of a containter affect the apparent mass of liquid inside it when measured by a scale? [duplicate]

For both containers it is true that: $p_{bottom}=p_{atm}+\rho gh$ and $F_{bottom}=a*p_{bottom} \iff F_{bottom}=a*p_{atm} + a\rho gh$ I do not know how a scale functions, but I guess that the only ...
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1answer
63 views

Mass of a point charge [closed]

A point charge is defined as an electric charge at a mathematical point with no dimensions(Wikipedia: https://en.wikipedia.org/wiki/Point_particle#Point_charge). Can anything be said about its mass in ...
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4answers
443 views

What truly is mass, and is there a direct way to measure it?

We know a mass of an object of one kilogram as an object that weighs W = mg = 9.8 N and we reference it to that, (when it should as a fundamental parameter describe weight not the opposite). But if we ...
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1answer
34 views

Doubts About Force and Inertia!

But then what does inertia mean at all!? Cant we calculate how much it resists the applied force? I mean considering an imaginary plane with no friction but gravity as of Earth and an enormous mass of ...
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1answer
66 views

Do we feel 0.4% less body weight on mount everest?

Weight of the object at surface of earth(where $g=9.8066$). considering Weight=$100~\rm kg$ ,Weight ($W_1$)=$mg$ , mass=$10.1972~\rm kg$ At mount Everest top: Height of Mount Everest = $8.848\rm ...
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2answers
115 views

Does center of mass affect how an object falls?

Suppose you drop an object which has tow ends, of which one is heavy and the other is pretty light. Will the object fall with its heavier end downward or with the lighter one? Why does it happen?
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2answers
27 views

Balancing Utensils: Center of Mass

If you have a cork piece on top of a nail, it is extremely hard to keep it stable, and the slightest action will make the cork fall off. However, when you balance it on top of a nail but put forks ...
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2answers
327 views

How can the Schwarzschild radius of the universe be 13.7 billion light years?

So i was reading about Schwarzschild radius on Wiki and I found a interesting thing written there link. It says that the S. radius of the universe is as big as the size of the universe? How is ...
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3answers
199 views

Inertia on relativistic mass when particle is near speed of light

Inertia is directly proportional to mass but what happens when something travel to speed near to light. Its relativistic mass tends to infinity but that is false mass so I want to know if inertia is ...
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2answers
54 views

Why is the mass of neutrino expressed in electronvolts?

The definition of electronvolt (eV) from wiki is In physics, the electronvolt (symbol eV; also written electron volt) is a unit of energy equal to approximately 160 zeptojoules (symbol zJ) or ...
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3answers
5k views

Relation between Newtons and Kilograms

Work is expressed as $W=Fd$, where the $F$ is in Newton, $d$ is in meters and result $W$ is in Joules. For example, if I take $1N$ on earth and lift it $1m$ up in the air I have done $1J$ of work. ...
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4answers
83 views

if mass is dependent on velocity, and velocity is relative, how can we determine rest mass [closed]

If I'm not mistaken, $m=\gamma*m_0$ ($\gamma$ being the lorentz transformation) But $\gamma$ depends on velocity. How do we determine velocity if velocity is relative? If we are currently being flung ...
16
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3answers
1k views

What is “mass” in particle physics? [duplicate]

It's clear, from reading pop-science articles about the Higgs boson, that particle physicists have something very specific in mind when they say "mass". In classical physics the mass of a particle is ...
1
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1answer
31 views

Is this equation for the rotational weight of a half disk correct? [closed]

I need to know what rotational force the weight of this disk applies to the axle. I'm not sure what the units are, whether it's torque or something else I'm looking for. The weight of the disk is ...
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1answer
33 views

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 ...
3
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1answer
48 views

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 ...
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4answers
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What's the difference between centre of mass & centre of gravity for massive bodies?

My book says: For most of the small objects, both are same. But for mammoth ones, they are really different ones. And in a gravity-less environment, COG is absent; COM still exists. Ok, what's ...
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1answer
36 views

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?
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4answers
2k views

If a spaceship were to be able to travel at light speed, would it pass through objects undamaged? Would it damage/destroy objects?

We know, not just by scientific theory, but by practice (I have seen it with my own eyes), that an increase in velocity increases the mass of the given object proportionally. One day visiting a ...
3
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0answers
58 views

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?
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3answers
55 views

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 ...
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1answer
94 views

Does scale invariance imply massless or continuous mass distribution?

$\newcommand{\ket}[1]{\lvert #1 \rangle}\newcommand{\bra}[1]{\langle #1 \rvert}\newcommand{\scp}[2]{\langle #1 \vert #2 \rangle}$ In his 2008 slides (PDF), Tzu-Chiang Yuan mentions the following on p. ...
4
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1answer
1k views

Fermion mass Higgs mechanism

How does a fermion, like an electron, get its mass through the Higgs-mechanism? Can someone explain me this with formulas (Lagrangian)? I know that the Yukawa interaction has something to do with ...
0
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2answers
41 views

Why the mobilities of holes and electrons are not identical in an intrinsic material?

In an intrinsic material, the lifetime $\tau$ of electrons and holes is the same, so in the equation for mobility, $$\mu = \frac{e\tau}{m^*}$$ the only difference between mobility of electrons an ...
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2answers
72 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 ...
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0answers
22 views

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 $d$ ...
3
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1answer
102 views

Is it experimentally proven that photons travel at speed $c$ in vacuum?

Are there experiments which show that single photons (not classical em waves) travel exactly at $c$ in vacuum? What is the error bar in that case? The question is posed due to the fact that loop ...
3
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0answers
30 views

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?
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If you double the mass of a moving object - is its kinetic energy quadrupled?

My colleagues and I were having a layman conversation about fuel consumption of boats vs planes etc. I was pointing out that according to the formula $$ E_k = \frac{1}{2}mv^2 $$ if you double the ...
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2answers
184 views

At What Point Does Mass Cease to Matter?

I know very little about physics so I naturally have a lot of simple minded questions. Assuming I am piloting a rocket and want to obtain the fastest speed possible. At what point does mass more ...
10
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2answers
440 views

For a particle to have physical mass, is it always necessary to have a mass term in the lagrangian?

Since the self-energy adds to the bare mass defined in the Lagrangian, is it possible to create a physical particle mass from the self-energy alone, with no mass terms occuring in the Lagrangian? On ...
1
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1answer
413 views

How is the fall time for a parachute affected by the mass of the load?

Why do parachutes with a heavier load fall faster than a parachute with a lighter load?
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3answers
69 views

Are all conserved scalars proportional to relativistic mass? [closed]

I have read in Rindler's relativity book that all scalars depend only on the magnitude of velocity of a particle and that are conserved are proportional to relativistic mass. ...
1
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0answers
25 views

Simulating Debris Burn Up Upon Atmospheric Reentry

For work I need to model Debris (1 gram to no more than 1000 km) burn-up upon reentry. I can't seem to find much information regarding this. I feel like I am looking for the wrong terms or something. ...
4
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1answer
10k views

Terminal velocity of two equally shaped/sized objects with different masses?

I've tried doing research on this and there are some similar questions. However, they have slightly different scenarios and to make sure I understand things perfectly, I wanted to word it into my ...
7
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5answers
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Does matter with negative mass exist?

Or does it exist mathematically? Is it really inconsistent with a common-sense, mathematics or known physical laws? As far as I understand, if it exists, it must be far away from the "positive" ...
3
votes
1answer
1k views

What bends fabric of space-time?

I know that mass can bend fabric of space-time, which causes gravity by making an object curve around a planet or star but is there anything else that can bend it? Other energy sources, forces ...
1
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1answer
39 views

What is the property which flows as described by the stress energy tensor in GR?

I found the following definitions: The stress–energy tensor (sometimes stress–energy–momentum tensor or energy–momentum tensor) is a tensor quantity in physics that describes the density and flux of ...
3
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0answers
47 views

What is the inertial mass of a black hole?

Or the inertial mass of any spherically symmetric object, can I calculated by measuring very accurately the spacetime distortion this object produces in its surroundings? With 'inertial mass' I mean ...
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3answers
98 views

How does a mass create the gravitational field of GR? [closed]

As far as I understand, and please correct me if I am wrong, but the basic idea of general relativity is that spacetime is curved by matter. What we call gravity is then not a force as per Newton but ...
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2answers
122 views

At relativistic speeds, how is an object's increased mass created and distributed?

This question says that, at relativistic speeds, an object's increased mass will result in increased weight or gravitational force. But if we have increased mass and corresponding gravitational ...
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1answer
68 views

Reason for not using Higgs mechanism to solve mass gap problem

I am curious as to precisely why one can't introduce masses for gluons in Yang-Mills by a Higgs-type mechanism as in electroweak theory. Is it because then one would end up with an unwanted massless ...
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0answers
26 views

Calculating electricity used for weights on an elevator

Given an elevator with a motor driven by a power supply, torque ability and a pulley does it take more electricity to lift more people? I have some of the calculations but do elevators lift at a set ...