# Tag Info

## New answers tagged mass

0

Depends on how you are defining "weight". If you mean weight as in the vector or scalar of the gravity acting on an object, Marco's answer is what you want. There is a third meaning of weight. This is essentially "what a scale measures". This definition also fits with how people typically experience the effects of weight. If we use that definition, then ...

6

For all practical purposes the weight will remain 1000 pounds when you freeze it. In theory the mass of the water will reduce somewhat through cooling because it will contain less energy when frozen, but the effect would be utterly negligible. Although the weight will be the same, water expands in volume by about a tenth as it freezes (which is why, for ...

1

If you look at the link you gave, the combined higgs mass is given as 125.18 +/-16. Differs from just Atlas. They have combined all possible seen channels and experiments to get at this accuracy. To see part of the complexity have a look at this talk at CERN. It is not simple.

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A particle of mass $m$ located at $\vec{r} = \pmatrix{x & y & z}$ from the origin, and having velocity $\vec{v} = \pmatrix{ vx & vy & vz}$ has the following properties Linear momentum $$\vec{p} = m \vec{v} = \pmatrix{m\, vx \\ m\, vy \\ m\, vz}$$ Angular momentum about the origin  \vec{L} = \vec{r} \times \vec{p} = \pmatrix{m ( vz\, y-...

1

Gravity is not “a negative value”. Gravitational force and gravitational accelerations are vectors whose direction is attractive. What this means is that, if you have two massive objects, each one experiences a force towards, and accelerates towards, the other one. Two masses attract even though both masses are positive. (As far as we know, all mass is ...

0

Yes it also includes the distance of centre of mass. The energy of the Bob is considered as the energy of the particle at the centre of gravity. So it should also take into account the Centre of gravity length.

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To be precise it is the length from the pivot point to the centre of mass of the bob. However the bob is usually considered as a point mass. On a more general note, the time period of any compound pendulum can be calculated as follows: http://farside.ph.utexas.edu/teaching/301/lectures/node141.html

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One could define "Komar-like" quantities for spacetimes which admit Killing vector fields, in general. But, whether they make sense is another question. It is known that there is no well-defined notion for the mass in asymptotically de Sitter spacetime since in such spacetimes the Killing vector of time translational symmetries is spacelike at future null ...

0

I disagree with the answer provided by @StefanoGariazzo. Oscillation probabilities are insensitive to the signs of $\Delta m_{ij}^2$ for all $i$ and $j$. However, the numbering of massive neutrinos, $\nu_{1}$ $\nu_2$ and $\nu_3$, is arbitrary. The usual convention is to number the neutrinos such that $m_2>m_1$ which makes $\Delta m^2_{21}>0$ by ...

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Yes, it is a mass term. Its the famous Majorana mass. You are coupling the left-handed particle to its right-handed antiparticle.

1

why don't we always lift stuff from it's center(center of mass) since it can help maintain balance of the object? Just an opinion, but I think it is because if we attempt to focus our force on the center of mass (COM) with one hand, but are off the COM, we need to apply a torque as well to counteract the moment of the center of mass about the point where ...

1

An object will rotate if ALL net forces combined do not center on the center of mass. Say you pick up a plate by the edge, with one hand, you will likely have some fingers on the bottom pushing up, and your thumb on top, farther outward toward the edge, pushing down. This will equalize the two forces at the center.

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I don't know what do you mean by "lifting from the center of mass" since the center of mass of, say, an empty homogeneous cubic box, is the geometrical center of it and there is just "air" there, no "box". Some notes on this anyway: if you don't want the object to rotate when lifting it, the torque on the object must be zero. There are different ways to ...

1

We almost always lift the object from its center of mass. When there are two people lifting an object or when we lift using both our hands, we do so from the opposite ends so that the net force is along the center of mass. If we don't do so, there will be an extra torque produced which will make it much harder to lift. However if the object is really small (...

2

Charge and mass are independent properties of a body. The center of mass and charge of a body depend solely on the way the mass or charge is distributed about the body. If both are distributed in the same way, their centers will coincide.

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One of the things I like the most about this question is the other insights we can infer from the possible answers. We are taught that mass warps spacetime, and the curvature of spacetime around mass explains gravity — but the exact manner by which this happens is still unclear. Curvature is also a seemingly arbitrary term, we cannot definitively say if the ...

1

When water is formed by burning hydrogen, energy is released. So a molecule of water is slightly lighter than two atoms of hydrogen plus one atom of oxygen. We can estimate the mass difference by using $E=mc^2$ on the enthalpy of formation of water. From the Active Thermochemical Tables of the Argonne National laboratory, we find that the enthalpy of ...

0

Physics at this point in time has arrived to the standard model of particle physics as the basis of all observations in the quantum mechanical frame. As all classical observations emerge from the underlying quantum frame ( except this is a hypothesis for the case of effective quantization of gravity) macroscopic states also follow the rules of the underlying ...

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This question is debated at length by those who are interested in the philosophy of time. The fact that so many philosophers of time can hold so many conflicting opinions about it (some of those opinions being at odds with physical fact) suggests that it is not one that is open to an easy or testable answer. Some take the view that things (mass, energy etc)...

2

That is an interesting question, and to answer it we need to deconstruct most of the notions used to ask it. First point: spacetime is a four-dimensional mathematical object which encompasses both space and time, so nothing moves through spacetime (motion is how position changes along time), and similarly nothing can be said as being persistent or not in ...

2

In general relativity the conservation of mass, energy, and momentum are captured in the covariant expression $\nabla_{\nu}T^{\mu\nu}=0$. This is a local conservation law which basically says that energy, momentum, and mass cannot be created anywhere at any time. If you draw a small 4D box in spacetime any energy, momentum, or mass that comes in one side ...

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The literature contains four (4) different formulas for the transformation of temperature and the history of the subject is itself quite interesting; I suggest you read the quite recent and openly available paper by Jiri J. Mares, Pavel Hubik, and Vaclav Spicka: "On relativistic transformation of temperature", DOI 10.1002/prop.201700018 and references ...

-1

My understanding is that the statement is broadly true. The energy states of electrons in atoms are described by solutions to the Schrödinger equation, the spatial distributions of which vary (you can see graphical representations of them on the internet if you google electron orbitals). Generally the solutions with higher energies have a wider spatial ...

1

Yes, but … it would not be called ADM mass, a proper term would be “quasi-local” rather than “local” mass (energy), there are many prescriptions for defining such mass (energy). Note, while literature often uses “mass” and “energy” interchangeably, sometimes a distinction is necessary: energy is a time component of a vector (energy–momentum), while mass ...

1

Very small. While it's possible for an individual atom to orbit, it's tricky. Once a macroscopic object is in orbit, you have to apply a large force quickly, or a consistent small force over time to remove it. With unbound atoms, tiny forces would remove it. Much of the interplanetary medium is plasma rather than neutral atoms. Those will be much more ...

1

A rough sketch of an answer: first, how do you tell whether something is a liquid or a solid? Say you measure viscosity: put the substance between concentric cylinders, apply a mild torque on the inner cylinder. If it moves a bit, and sticks, you have a solid, if it reaches a constant angular velocity, you have got a liquid. Clearly, even the fastest ...

1

Yes. For example, when a hydrogen atom absorbs a photon and transitions from the $1s$ ground state to the $2p$ excited state, with 10.2 electron-volts more energy, its mass increases by $1.8\times 10^{-35}$ kilograms, or about one part in 100 million. This is just $\Delta m=\Delta E/c^2$.

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