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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.

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Formulation of Newton's second law: $F=ma$ or $a=\frac{F}{m}$?

Assuming a constant mass, which would be best way of expressing Newton's second law? $F=ma$ or $a=\frac{F}{m}$? The most common way is the first one, but I feel more comfortable explaining it the ...
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What is heavier, water or ice?

I was reading this link and I never saw a definite answer. One would think if you have 1000 pounds of water, and you froze it and weight it you would still have the same 1000 pounds of water when ...
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Pendulum: Time period for effective length varying with angle

For a pendulum whose effective length changes with angle, my approach would be to write the length as a function of the angle: $\ell(\theta)$, then using the torque derivation of the time period I do ...
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Has the gravity a negative value?

We all know that the acceleration of the gravity is equivalent to 9.81 m/s². But the gravity attract everything that have a mass (everything as far as i know) to the center of a planet. As an ...
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Rate of angular momentum at the center of mass

I'm currently trying to calculate the Zero Moment Point for a game I develop, however im terrible at physics and therefore have trouble calculating the “rate of angular momentum at the center of mass”....
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Does the length variable in pendulum motion include center of mass?

In diagrams, is the bob/mass of the pendulum considered a point, or a 2/3D object? And furthermore, is the length variable in the period of a pendulum simply the length of the string, or is it really ...
71 views

2019 Higgs Boson Mass?

Wiki, based on the 2018 Particle Data Group, gives the Higgs boson mass as $125.18 \pm 0.16$ GeV$/c^2$. OK. However, 2017 ATLAS gives a combined value of $124.98 \pm 0.28$ GeV$/c^2$. So what is ...
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Why can't a Weyl Fermion have mass?

My understanding was that a particle may have mass if there is a quadratic term in the fields without derivatives. For a single left-handed Weyl fermion, the following expression is lorentz invariant, ...
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Is there a difference between a electronic force restoration balance and a Kibble balance?

At least from the description of the working principle, the typical analytical balance seems to use the same principle used by Kibble - Watt balance to realize the international standard kilogram from ...
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Why don't we always lift stuff from center (center of mass)?

if you lift a large box alone, you try to lift it from the Center(Center of mass),but if the box is small you just use both of your hands each grabbing a side of the box(not from center of mass). if ...
38 views

Is the centre of charge always within the centre of mass of an object?

What I am confused about is whether the charge of an object is concentrated within the centre of the mass itself, or does it change depending on the situation?
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$H_2O$ vs $2H^+ +O^{2-}$

I am wondering the mass deficit between 2*H + O and H2O. I.e. if I would know the accurate mass of one atom of hydrogen on it's own and the mass of one atom of oxygen on it's own how much of a ...
108 views

Is mass persistent in spacetime?

As an object moves through spacetime is its mass persistent? What I mean is, if we find a way to look backwards into time, will a pen sitting on a desk when I was in college still be sitting on that ...
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Possible proof that the universe can not have infinite mass? [duplicate]

I was thinking about the possibility of the universe having infinite mass, but then it occurred to me that it would then perhaps violate conservation of mass. Here is my thought process: Assuming ...
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Does $E=mc^2$ apply to electron shells with different energies? [duplicate]

Is this statement true: Each electron shell has a different energy level, with those shells closest to the nucleus being lower in energy than those farther from the nucleus. Mass of electron \$= 9....
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What is the total mass of orbiting interplanetary unbound atoms in the solar system?

Excuse the poor phrasing of the title, but it became apparent to me that the solar system has some degree of density (i.e it is not a perfect vacuum). So my question is if any of these particles (not ...
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What would be the properties of an anti-black hole (concentration of negative mass)?

What would be the properties of an anti-black hole (concentration of negative mass)? Would it emit radiation? Would time go infinitely fast on its surface?
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Can the ADM mass be defined locally inside a closed surface?

To calculate the ADM mass, one has to specify a closed surface inside which all the mass is located. Are there any ways to calculate the mass inside a closed surface outside of which other mass still ...
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Mass and energy of radiation

We know that mass can be  converted to energy and vice versa. So does the mass of molecules or atoms change when they absorb a radiation and go to the higher energy state?
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Will gravitational field of a body increase if the body is accelerated? [duplicate]

Suppose a body is at rest of mass m. If the same body is accelerated at velocity v, the mass increases to some definite amount. Since the mass of the body has increased, will the gravitational field ...
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Black hole mass

It has been taught to us that since the black holes have finite mass, their gravitational force is also finite, which totally fits. The Black hole anyhow has a singularity at it's center which is ...
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What is the significance in determining the mass of a black hole? [closed]

Was just wondering the importance of the mass of a black hole
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Paradox regarding phase transitions in relativistic systems

The main question I would like to ask is whether quantities such as density are dependent on the frame of reference. I have searched several forums and the answer is somewhat controversial. Some ...
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How to estimate the mass of an incoming asteroid?

A second galactic visitor has just been observed: see this link. For a mass which is small enough to have no noticable effect on other masses, is there any other way to infer the mass? Its own motion ...
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Does light have mass? Why? [duplicate]

I've been wondering whether light has mass. Yet given the wave-particle duality of light, the statement seems to be affirmative. With that, how to calculate it?
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Is there a Mass-Temperature relationship for main sequence stars?

When finding relationships between various properties of stars, I frequently find next to nothing on the Mass-Temperature relationship. I, of course, see the Mass-Luminosity and the Luminosity-...