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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Rotational dynamics equation for a variable mass system?

I'm searching for the formulation of Euler's rigid body dynamics in the case of a variable mass system. I'm reading the book Mechanics of Flight by Warren F. Phillips (2nd edition) and unfortunately ...
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3answers
2k views

If there is no gravity, does that mean there's no mass as well?

I have demonstrated that weight only is measured based on the gravitational pull of where you live. For example, the gravity on the surface of Mars is three times smaller than the gravity on the ...
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4answers
83 views

Why is the definition of mass and matter interlinked?

In my textbook the definition of matter and mass are: Matter: Any thing that occupies space and has mass . Mass: The amount of matter contained in a body. While defining "matter" we refer to ...
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3answers
3k views

If something weighs 25 kg, how do I find the mass of the object?

An object is falling and it weighs 25 kg (on a scale, presumably). What is its mass? I know that weight is measured in Newtons and mass in kilograms, but what if a problem states that something ...
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3answers
101 views

The relation between mass and speed

Massless particles (or luxons) have no (rest) mass ($m = 0$) and a speed equal to the speed of light ($v = c$). Massive particles (or bradyons) have mass ($m > 0$) and a speed lower than the speed ...
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50 views

Maxwell said the dimension of charge is $L^3 T^{-2}$ and of mass is $L^3 T^{-2}$, is he right? [on hold]

If his right then, from Lorentz magnetic force, $$F= BQV$$ where $F$ is force, $B$ is magnetic flux density, $Q$ is charge and $V$ is velocity. Therefore, $$M L T^{-2} = B Q V \, .$$ Substituting for ...
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24 views

Is density of an element directly proportional to atomic number or atomic weight? [duplicate]

Is the density of an element directly proportional to any power/order of atomic weight or atomic number? I know very less, probably only highschool level physics, after which my brain has been ...
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2answers
988 views

An atomic bomb explodes inside of an “unbreakable” container which is on a scale. Does the “weight” of the container change?

I read that most of the "mass" in the proton was actually energy from the quarks and gluons, as opposed to the actual mass which was coupled to the Higgs field. This made me start thinking about ...
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1answer
81 views

What happens to theoretical physics if a photon has non-zero mass?

I want to know the theoretical implication if photons have a non-zero mass. What happens to the Maxwell equations? What happens to QFT? If the photon have mass it can decade?
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3answers
81 views

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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1answer
62 views

How many human cells will get affected at the prick of a pin? [closed]

Wikipedia states that there are 10^14 cells in a human body. My question is if I was to take a needle or a pin and pierce it just 2 mm in the body, how many cells will I be piercing?
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5answers
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Can we find actual rest mass of things on Earth

Earth moves around the Sun and the Sun moves around the galaxy and the galaxy moves with unknown speed and direction. We have speed so the mass of us all altered. Can we know the real rest mass? If ...
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2answers
35 views

How is mass conserved when a muon decays?

A small disclaimer: I am a layperson and not a formal student of physics so forgive any glaring stupidity betrayed in the nature of the question. A muon is supposed to always decay into an electron ...
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4answers
198 views

Why is the momentum of a particle $\gamma mv$?

I am very new to relativity, and as I was going through Resnick & Halliday, I saw that momentum was no longer $mv$, rather $\gamma mv$. This was the proof: $$p = mv = m \frac{\delta x}{\delta ...
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0answers
37 views

Bottle stableness optimization

A few days ago me and some friends played a game where you need to upset a bottle with a ball(flunkyball). Then a question occured: "How much water do we need to put into the bottle that its ...
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2answers
38 views

How the mass is conserved during continuous expansion?

If universe is continuously expanding doesn't it contradict the fact that mass is conserved? Because if mass is conserved so how is universe expanding?
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0answers
27 views

How do scientists measure miniscule constants like the mass and charge and speed of an electron?

What can measure the extremely tiny mass of an electron? Is it through indirect means? The same goes for charge. The pull of a single electron must be infinitely small. And if one is to attempt to ...
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1answer
20 views

Taking a derivative in a dynamic mass balance?

I'm practicing for a transport phenomena exam and I came across this question: A mothball with a diameter of 1.0 cm is hung (by a thread) in stationary air. Mothballs consist of pure naphthalene. ...
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1answer
72 views

Feathers and Human Flight

In the case of Angels where they're supposed to have wings full of feathers and can fly. If we created a flight suit for humans made out of feathers, how big would the feathers have to be? If the ...
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3answers
87 views

How can you explain objects of unequal masses falling at the same rate using GR?

Isn't gravity caused by the curvature of space-time, and the stronger it's curved the stronger the attraction? it makes more sense to me that if a heavier object is falling on earth it would fall ...
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3answers
260 views

Deceleration rate of objects of different mass but the same otherwise

Using a tennis ball as an example object, if one ball weighs 1 ounce and the other is 2 ounces, and both are struck at 100 mph on the same trajectory, would there be any difference in the deceleration ...
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3answers
6k views

Does a photon exert a gravitational pull?

I know a photon has zero rest mass, but it does have plenty of energy. Since energy and mass are equivalent does this mean that a photon (or more practically, a light beam) exerts a gravitational pull ...
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1answer
381 views

Question about finding $k$ in Hooke's Law

My textbook (Advanced Engineering Mathematics by Dennis Zill) offers the following explanation of Hooke's Law: By Hooke's Law, the spring itself exerts a restoring force $F$ opposite to the ...
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2answers
352 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 ...
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3answers
298 views

What is the use (/ meaning) of $F =ma$? [closed]

I have noticed that Euler's formula for force is useful with a couple of natural forces (at distance), like gravity, that can follow a body any length. If you consider the most common occurrences of ...
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3answers
5k views

What did Tesla mean by “there is no energy in matter”?

I was reading "THE ETERNAL SOURCE OF ENERGY OF THE UNIVERSE, ORIGIN AND INTENSITY OF COSMIC RAYS" by Nikola Tesla, and he states: "There is no energy in matter except that absorbed from the ...
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1answer
65 views

Are there any naturally occurring examples of photons without mass?

I read that a photon is said to have zero mass at zero velocity. Does this mean that they only exist in a state of probability until observed && interacting with some system? And then when ...
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2answers
7k views

Preventing a block from sliding on a frictionless inclined plane

I want to demonstrate what force $F$ you would have to exert on an inclined plane of angle $t$, mass $M$ to prevent a block on top of it with mass $m$ from sliding up or down the ramp. I worked out ...
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1answer
41 views

Mass scaling in molecular dynamics

I've noticed some authors scale the mass of particles in molecular dynamics simulations while leaving the force field parameters the same in order to achieve materials of different densities. Does ...
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2answers
40 views

Can change in temperature cause a change in mass of an object?

If a gold bar is heated to say 200 degree Celsius then will it have the same mass at say 10 degree Celsius. Does energy has mass? If so then does this increased 'heat energy' cause an increase in the ...
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0answers
69 views

Does negative mass reverse the arrow of time?

General relativity predicts that normal mass (positive mass) results in the curvature of spacetime which in return leads to gravitation. Since space and time are bonded together, any change on the ...
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43 views

How to calculate the mass of a sun that is similar to our own

How would you calculate the mass of a sun that could host a habitable planet, with only given the values of the mass of our own sun. And the fact that it takes a specific amount of years for life to ...
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1answer
500 views

Why does mass in the universe have no limit in large size, but has a limit in small size?

We found VY Canis Majoris, a star so big it can't even be seen in scaled illustratations with the sun itself. However, we stop at particle physics, or quantum mechanics, i.e. particles, subatomic, ...
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2answers
1k views

How did Newton find out gravity is proportional to the product of two masses? [duplicate]

I am going to ask a really stupid question here. It is a very well known fact that gravity is inversely proportional to the distance squared between two masses. I understand how he arrived at this ...
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4answers
95 views

Units about weight

We know that weight is measured in Newtons. Since, $weight= mass\times gravity$. What will be the units of Newton? Will that be $N = kg\times g$ ? But we always measure our weight using the unit $kg$! ...
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6answers
4k views

Do photons gain mass when they travel through glass?

Please correct me if I'm wrong, but I believe that photons slow down when travelling through glass. Does this mean they gain mass? Otherwise, what happens to extra kinetic energy? I understand now ...
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1answer
39 views

Elements of particle mass

From what I can tell, it seems that particles have two kinds of mass, the mass inherent in a fundamental particle itself, or for composite particles, additional mass associated with the Higgs field. ...
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2answers
56 views

Connection between moment/torque and centre of gravity?

So I understand how moments work with regards to basic examples like pushing a door, in that the further you are away from the hinges of the door, the greater the moment, which is like a turning ...
117
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8answers
26k views

Don't heavier objects actually fall faster because they exert their own gravity?

The common understanding is that, setting air resistance aside, all objects dropped to Earth fall at the same rate. This is often demonstrated through the thought experiment of cutting a large object ...
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3answers
3k views

First and Second Moment of Mass

I recently came across the definition of the Center of Mass of a system as the point about which the first moment of mass is zero. Further, it defined Moment of Inertia as the second moment of mass. ...
4
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0answers
39 views

Why are $W$ bosons massless above electroweak scale? [duplicate]

Because of the Higgs mechanism, one must replace the Higgs field $\phi$ with $\phi_0 + \phi_1$ where $\phi_0$ is the vacuum expectation value. As far as I understand, the $\phi_0$ gives the mass term ...
6
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3answers
678 views

Where does the majority of the mass of the usual matter come from? [duplicate]

I apologize in advance to experts for the naivety of the question. It should be a duplicate but I didn't find any satifying question or answer about that. The proton is composed by two up quarks ...
3
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1answer
43 views

Do we weigh more when standing near massive buildings?

I'm very new to the concepts of SR/GR and curvature of spacetime. My understanding is that the bending of spacetime is the causation of gravity, and that matter is the causation of the bending of ...
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0answers
36 views

How black hole lose mass? [duplicate]

Even in empty space virtual particles can constantly pop in and out of existence in pairs, when 1 of the pair fall into the black hole while the other escape this is hawking radiation but black hole ...
8
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2answers
2k views

What is the difference between pole and running mass?

For example, when we meassure Higgs boson mass to be 125 GeV, do we think about renormalized or pole mass? Should the mass of the Higgs change if it is produced at higher energies?
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1answer
75 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 Unparticle Phenomenology (PDF), Tzu-Chiang Yuan ...
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1answer
62 views

Pressure, density, volume and mass in a room

Here's the question. A window in the room is open. The next day, the temperature of the room has increased, but the pressure of the air stayed the same. State and explain what has happened to ...
2
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3answers
425 views

Why do non-accelerating objects exert force on each other?

The equation for force is $\vec{F} = m\vec{a}$, where $\vec{a}$ is acceleration. Acceleration is a change in velocity. However, if an object with constant velocity (i.e. 0 acceleration) hits another ...
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1answer
97 views

Commercial large scale production of graphene

I am a third year undergraduate Physics student, and for my solid state physics course I am asked to give a short (10 minute) qualitative presentation on the current standings of graphene production, ...
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1answer
144 views

Current known *lower* bounds to the neutrino masses?

I started a little bit of Googling around the topic, and found very few information. There are mainly upper limits. I found lower limits only to the rest mass differences of the different neutrino ...