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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81 views

Is it possible that Einsteins famous equasions $E=mc^2$ is slightly incomplete? [on hold]

I don't know much about physics, but I plan to be a physicist some day. I noticed Feynman diagrams show antiparticles moving backwards in time. Wouldn't that mean that they are moving faster than ...
1
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1answer
30 views

Are all ground state protons the exact same mass and have the same number of elementary particles?

I have read that it is a misconception that a proton only has 3 quarks (2 up and one down). In reality, it seems there are many, many ("zillions" is the number I saw quoted) quarks in a proton. Do ...
20
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4answers
3k views

Will 1 gram of matter moving at relativistic speeds completely annihilate a larger quantity of stationary antimatter?

This is a question about the relativistic mass concept which I am having trouble understanding, mainly because of the scenario below. Simple scenario: Suppose 1 gram of matter is accelerated to 99% ...
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1answer
46 views

Kettlebell squats center of mass

I should, first of all, state that I have very limited knowledge of physics but as a fitness enthusiast the following question has puzzled me for a while. When I do squats on the gym holding a ...
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2answers
76 views

A different interpretation of $E=mc^2$ but no idea what it might mean [on hold]

I wanted $E=mc^2$ to look like an 'inverse square' sort of a formula. So this is what I derived: $E=mc^2$, so; $m=E/c^2$, assuming $E=E_1E_2$ (I am aware that when you decompose energy into two ...
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2answers
30 views

How to calculate centre of mass

How do I find the centre of mass with given coordinates? For example if we have four objects with mass $m$ at coordinates of a square $(0,0,0),(0,0,a),(0,a,0),(0,a,a)$ or another example with eight ...
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3answers
48 views

How do we measure mass?

How do you measure mass? Weight is easy using a scale, but we can't measure mass that way, because then mass would be different on every planet. I know there was a Veritasium video (here) on defining ...
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4answers
72 views

How to measure the mass of Earth?

I was wondering how you can measure the mass of Earth. From what I find on the internet, people are using Newton's Laws. But how can you do that ? Newton's Laws are assumed to work because you know a ...
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1answer
16 views

Center of mass of planar lamina

Suppose that $D$ is a closed region in $\mathbb R^2$ and let $\rho$ be a density function on $D$. Then, is it possible that the center of mass lies on the boundary of $D$? My intuition tells me that ...
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0answers
23 views

Can anyone list all the ways the gravitational force interacts with the electromagnetic at our energy scale? [closed]

Apart from weight does the gravitational force manifest itself in our world in any other way?also, are these two different questions?
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0answers
28 views

How do we measure mass distribution in an object?

Given an object I want to know the mass distribution among different section. What are the inexpensive methods to know this ?
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3answers
120 views

Is it true that all particles that have a speed less than the speed of light must also have mass?

I've previously learned that massive particles cannot achieve the speed of light. But recently I read that, concerning the gels that refract and bounce light within around enough that it can travel ...
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1answer
26 views

Is it possible to make use of the gluon field's energy to use is applications?

As we know most of the mass of the proton comes from the energy caused due to the interactions of the quarks with the gluon fields (reference link of this statement ...
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1answer
28 views

Does mass distribution/center of mass affect free fall?

An everyday is example would be cars. If you were to drop a car, not taking air resistance into account, would a front-heavy car tumble forward as it fell? And a car with a perfect 50/50 front/rear ...
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1answer
42 views

How can light experience a force [duplicate]

According to the second law of Newton f=ma only objects with mass can experience a force. But light can be bent by gravity and is not supposed to have a mass. How ...
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2answers
34 views

In the Ideal Gas Law, what does “fixed amount” of gas mean?

Does it mean mass? If so, wouldn't Pressure/Temperature basically represent its density?
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1answer
34 views

Speed, weight and force [closed]

If a road roller of weight $W$ is rolling on the road at the speed of $X\,\mathrm{kmph}$, how much force does it apply on the surface of the road (considering a sampled surface of the same size as ...
2
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1answer
87 views

Clarification with Einstein's explanation of inertial mass and gravitational mass from his book

In the book "Evolution of Physics" - Albert Einstein and Leopold Infeld, the following explanation is given for two types of masses: A body at rest gives way before the action of an external ...
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5answers
136 views

Can the mass of a body change under any condition or not? [closed]

We know that mass can neither be changed nor be destroyed, but I want to know if there is any circumstance under which the mass of a body can be changed?
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2answers
30 views

How to increase flow rate? [closed]

I am coming up with ideas of how to increase grain (corn, soybeans etc,) flow in a tube. My first idea is to have spiral ribs inside of the tube to create a vortex effect that will allow the grain to ...
0
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4answers
79 views

How is gravity proportional to space-time curvature in the rubber-sheet analogy?

In General Relativity, Einstein established that gravity is due to the curvature produced by objects in space. We all know that gravity is proportional to mass. The picture Einstein painted looks ...
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1answer
52 views

Is the $\nu_e$ massive?

Neutrino oscillations imply that the $\nu_\tau$ is more massive than the $\nu_\mu$, and the $\nu_\mu$ is more massive than the $\nu_e$, so it's inferred that the $\nu_\mu$ and $\nu_\tau$ have mass. ...
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0answers
17 views

Is there any evidence for the increase of mass due to time dilation also causing a strengthening in said mass' gravity? [duplicate]

Logically it make sense that gravity would strengthen with an increase of mass but I want to know if there is evidence for this.
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1answer
63 views

How can electromagnetic waves be affected by gravity if photons have no mass? [duplicate]

I have found answers that say that gravity interferes with the oscillating electric and magnetic fields of the waves and others that say that since gravity is a bend in space-time, in which case the ...
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0answers
28 views

What is the difference between mass defect and mass deficit?

Is there any difference between the mass defect and the mass deficit? I have read that the mass defect of a nuclide is never negative and have also been told that the mass defect is the same as the ...
2
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2answers
90 views

How are weights and scales used by the public calibrated?

My physics teacher has a set of masses: things from 1 to 10 grams. My chemistry teacher has electronic balances that measures things in grams. In France, there is a block of metal we hope no one ...
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21 views

What will be the content of mercury of a can which contains 100 gm water?

What will be the content of mercury of a can which contains 100 gm water? (Density of mercury = 13.6 gms / cu.cm.) Ans: 1360 gms I just don't understand the question. I know it's easy but ...
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1answer
51 views

Find the center of mass of a hemispherical shell

Problem: Find the center of mass of a hemispherical shell of constant density and inner radius r1 and outer radius r2. Attempt at Solution: Let the hemisphere be in the region $z>0$. By symmetry, ...
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3answers
99 views

Does dark energy work like gravity, but the opposite way?

If a body has more mass gravity will exert a greater force on it. Does that apply also to dark energy? In other words, if a body has more mass, will it be affected more by dark energy? (that is, will ...
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6answers
737 views

Is (rest) mass conserved in special relativity?

I don't understand why it is said that the (rest) mass of a system is not conserved in relativity. I mean, the momentum of a system is conserved (i.e.: it remains constant in a frame of reference ...
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1answer
69 views

Minimum size of black hole

What is the minimum size a black hole could be? I have been told that they were worried that the LHC would create a black hole, yet they say the Sun cannot be a black hole. I understand that the ...
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1answer
14 views

Is density of a material related to penetration?

Theoretical question. If you have a standard projectile with mass 1 and velocity 1 and fired it at different materials would the penetration be related to the density of the material? I'm not trying ...
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2answers
40 views

Does the gravitational force of one object interfere with that of another?

Assume we have two iron spheres, Sphere A and Sphere B, with identical masses floating in the vacuum of interstellar space separated by some distance from each other. The gravitational force of each ...
1
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2answers
98 views

How can a photon have energy when its mass is zero? [duplicate]

How can a photon have energy when its mass is zero? According to Einstein's equation $E = mc^2$ energy depends on $mass*c^2$ Light has zero mass so the energy would be zero too but solar cells use ...
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0answers
30 views

What will happen when an unstoppable force meets an immovable object? [duplicate]

I was thinking when this question came to my mind. What will happen when an unstoppable force meets an immovable object?
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1answer
104 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 this ...
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3answers
103 views

Why would the curvature in space-time attract photons which have zero mass? [closed]

I know that we are surrounded by dark matter, does the dark matter affects space time ???and I know the reason for gravity according to explanations in general relativity. But all the explanation ...
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2answers
97 views

Does mass curve space?

Just to be sure, according to the theory of General Relativity, my understanding is that mass curves space-time. My question is, can mass also curve space?
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4answers
105 views

What exactly is the mass of a body? What determines it?

The term "mass" is very common. But what does it depend on? How is it known?
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2answers
67 views

Are black holes an infinite source of energy? [duplicate]

Black holes are considered particularities because in a determined point in time they are pointless, as consequence there are some mass in a null space so the density become infinite. Finally if ...
0
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1answer
74 views

Deriving the Lorentz factor

Recently, I learned how to derive E = mc^2. However, to do so, one must accept the relativistic mass equation. How does one derive this?
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1answer
43 views

Metric in Lagrangian and the minimum total potential energy principle

I was wondering why physical systems "like" to go to the minimum of potential energy and I found this question, that tries to justify the minumum total potential energy principle. I was also reading ...
1
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0answers
26 views

Interpretation of Mass Continuity Equation in MHD [duplicate]

I'm writing up my final-year dissertation and I'm required to give, as part of the introduction, an analysis of all the equations (and their terms) of which I use. Embarrassingly, whilst of course ...
0
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1answer
60 views

Could gravitational waves and electromagnetic waves/light be the same thing? [duplicate]

They travel at the same speed, why? Maybe they are the same thing, but seen from different perspectives.
0
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1answer
47 views

Smallest Black hole nessesary to devour Earth?

While looking into black holes I can across the idea of hawking radiation, and the fact that microscopic black holes would near instantaneously evaporate before doing any damage. However larger black ...
42
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5answers
6k views

Why is the prospective new kilogram standard a sphere?

I can understand the choice of material, silicon 28, but why is it a sphere rather than (say) a cube? Article here I would have thought that a sphere would have been the hardest shape to machine ...
4
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1answer
47 views

How much mass is typically ejected from a supernova?

How much mass is released from a supernova of a 15 solar-mass star? 20? 25? What is the relation between star mass and mass ejected?
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0answers
41 views

What happens to the d/dr term of the continuity equation in cylindrical coordinates?

The derivation of the continuity equation in cyclindrical coordinates should look like this, $$ \dfrac{dm_{cv}}{dt}=\sum \dot{m}_{in} - \sum \dot{m}_{out} $$ where $$ m_{cv} = \rho r ...
2
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1answer
35 views

Is it possible to calculate the information content of matter? How?

I know the Bekestein bound is the upper bound for the information content of a region of space, but is it possible to actually calculate that information content (number of bits, not the bits ...
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1answer
61 views

Real-world evidence that non-massive entities (or even: antiparticles), and their behaviors, are sources of gravity?

The theory of general relativity tells us that non-massive entities, and their behaviors, are possible sources of gravity. Mass isn't needed, the theory says. What's the real-world evidence that ...