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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3answers
68 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 one,...
0
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1answer
45 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 ...
1
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1answer
101 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 ...
3
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1answer
97 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 = $8.848\rm km$...
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2answers
39 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
87 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 1.6×...
1
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4answers
107 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
38 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 $...
0
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1answer
39 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 ...
1
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1answer
117 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?
3
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1answer
52 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 ...
3
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0answers
61 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
124 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 ...
2
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2answers
104 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 ...
0
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1answer
136 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 ...
1
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1answer
93 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
votes
1answer
72 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?
3
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1answer
120 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 ...
1
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2answers
189 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 ...
-1
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3answers
71 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. $$m(\vec{v})=m_{0}/\sqrt{...
1
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0answers
26 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. ...
1
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1answer
46 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
58 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 ...
0
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3answers
121 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 ...
0
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2answers
133 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 ...
1
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1answer
97 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 ...
0
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0answers
38 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 ...
0
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0answers
17 views

if a meteorite is moving in space fast enough to generate a lot of mass shouldn't it generate gravity because its moving? [duplicate]

is it how planets form when is happens to have alot of mass to generate a little bit of gravity, oh and bullets for example they generate mass when moving and causes it generate mass?
1
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2answers
99 views

Rest mass energy of electron

For electron's energy why we some time use the word "REST MASS ENERGY" why we use this word as electron is always spinning?
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1answer
143 views

Is it true that the standard model does not predict the mass of the electron?

I read that the standard model has parameters that have to be put in such as the mass of the electron, because nobody has been able to calculate the mass of the electron. Is this true?
1
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0answers
23 views

Is photon massless? [duplicate]

if photon is massless then in E2=m2c4+p2c2 is m=0 ? and p=mv1-mv2 shouldnt be zero too. if both the statements are true then does photon has no energy?
1
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2answers
75 views

Period of mass in circular motion [closed]

I've been trying for 4 days now to solve my physics lab assignment but now I'm starting to think there must be a mistake in the question. You know those rotating mass experiments where you have a mass ...
5
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3answers
406 views

Zero $g$ in a black hole?

At the very centre of the Earth, masses cancel each other out, creating an effective zero-$g$ environment. Would the same happen in a black hole?
-3
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1answer
56 views

3D donuts and the centre of a black hole [closed]

I have been trying to imagine ways to visualise the gravitational field of the earth... It's near zero at the outer edges of the atmosphere, strong at sea level, strongest at the quarter point, then ...
0
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2answers
74 views

Does it take a larger force to stop a faster object?

Does it take a larger force to stop a car that is moving at a velocity 2*v than if it is moving at a velocity v? I'm confused as the force required to decelerate a car depends on the mass and the ...
3
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1answer
60 views

Effective mass of two objects

I read that if we want to perform conservation of energy taking one object as frame of reference, we need to assume that the other object has the effective mass and velocity. And effective mass is ...
2
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3answers
41 views

What is the gravitational pull if one has as much mass above them as below them? [duplicate]

I understand the previous responses to other answering if you were at the center of a planet, would you be weightless? Yes you would due to the forces of gravity pulling at you from all sides. ...
0
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0answers
35 views

What is $r$ in angular momentum quantization rule?

We know $$mvr= nh/2π $$ What is $r$ here if I consider positronium system. I suppose it should be the radius of the orbit in which both are moving. But when I take the above equation and electrostatic ...
0
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1answer
35 views

How to calculate relativistic mass versus time?

I know that relativistic mass is calculated as: But when mass m0 gets bigger, also mass of the accelerating body mass m gets bigger so m0 gets bigger and so on. So if body accelerates with ...
0
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2answers
45 views

Remotely finding the mass of a satellite

I have a question similar to one I've asked earlier (Calculating mass of an orbiting body with force and acceleration), but without a specific formula... How can you find the mass of a satellite body ...
3
votes
3answers
102 views

Why does a teeter-totter (see-saw) tend to incline towards the heavier end?

Why does a teeter-totter (see-saw) tend to incline towards the heavier end? Since objects of different mass tend to fall at the same speed (assuming a vacuum), why do then heavier objects push harder ...
0
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2answers
58 views

Double the mass in the universe, double the inertia

If I double (halve) the mass in the visible universe, will my inertia double (halve)? I think it should, at least as soon ''I have received the news of this doubling''. But what does the General ...
0
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1answer
72 views

Constructing a Hamiltonian from a mass matrix?

I was solving some questions regarding the Hamiltonian, which required a lot of algebra, but as I finished and looked professor answer I saw that he constructed a matrix from the kinetic energy and ...
0
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4answers
86 views

Proving that the Center of Mass of a solid sphere is at the origin [closed]

For my own knowledge and to understand why. I am trying to convince myself that the center of mass for a rigid solid sphere is at the origin (0,0,0). I begin with the basic definition of CM $$\...
0
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1answer
46 views

How to derive an equation for the mass of a pendulum bob?

How to derive an equation for the mass of a pendulum bob? If anyone knows of a resource that shows this (I've looked) or could explain how to derive an equation for the mass of a pendulum would be ...
0
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2answers
76 views

Negative Mass Square

I'm reading a book about neutrino physics (from 1997). In the chapter about neutrino mass they list results of certain experiments. All of them get a negative value for $m(\nu_e)^2$ but a positive one ...
0
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0answers
42 views

Point of zero gravity for fixed masses?

Given a number of fixed point masses in 3D space, is there necessarily one or more points where there is zero gravity (ie, the combined gravity of the masses cancels out), and, if so, how do I find ...
0
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0answers
34 views

Charged Universe and charge-dependent inertia/anti-inertia

I posted this same question as a follow up for the main question here. I expected to get a quick answer but since none have come up I raise it as a topic in its own right. So the question is: Suppose ...
0
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2answers
65 views

How much Oxygen is in ζ-phase metallic Oxygen?

I am playing with a sci-fi idea of Oxygen storage for breathing. I wonder how do some compressed forms of Oxygen compare to human-breath-Oxygen (room temperature, room pressure) in terms of density. ...