What is Mass-energy equivalence: Definition and 24 Discussions
In physics, mass–energy equivalence is the relationship between mass and energy in a system's rest frame, where the two values differ only by a constant and the units of measurement. The principle is described by the physicist Albert Einstein's famous formula:
The formula defines the energy E of a particle in its rest frame as the product of mass (m) with the speed of light squared (c2). Because the speed of light is a large number in everyday units (approximately 3×108 meters per second), the formula implies that a small amount of rest mass corresponds to an enormous amount of energy, which is independent of the composition of the matter. Rest mass, also called invariant mass, is the mass that is measured when the system is at rest. It is a fundamental physical property that is independent of momentum, even at extreme speeds approaching the speed of light (i.e., its value is the same in all inertial frames of reference). Massless particles such as photons have zero invariant mass, but massless free particles have both momentum and energy. The equivalence principle implies that when energy is lost in chemical reactions, nuclear reactions, and other energy transformations, the system will also lose a corresponding amount of mass. The energy, and mass, can be released to the environment as radiant energy, such as light, or as thermal energy. The principle is fundamental to many fields of physics, including nuclear and particle physics.
Mass–energy equivalence arose from special relativity as a paradox described by the French polymath Henri Poincaré. Einstein was the first to propose the equivalence of mass and energy as a general principle and a consequence of the symmetries of space and time. The principle first appeared in "Does the inertia of a body depend upon its energy-content?", one of his Annus Mirabilis (Miraculous Year) papers, published on 21 November 1905. The formula and its relationship to momentum, as described by the energy–momentum relation, were later developed by other physicists.
I was finding the energy required to separate tritium into it's component parts, the binding energy when it hit me that how could 1amu= 931.2 MeV and 1.66e-27 kg at the same time?
I'm an amateur physics enthusiast, and there is a question that's been in the back of my mind for some time that I haven't been able to answer on my own, and haven't gotten a satisfactory answer elsewhere. First, I want to define a couple of terms and make sure my understanding isn't breaking...
Hi,
today I stumbled upon a 2016 article in Scientific American about the (then) possibility of re-defining the kilogram through Planck's constant.
The article is really a very quick review of the topic. At some point the author states the following "So for years, physicists have chased an...
How well is the transition between energy and mass understood? Energy can turn into matter and matter can turn into energy but what is actually happening between the two states? Imagining that matter just simply appears and disappears under an infinitesimal amount of time feels weird to me.
I think mass as a form of potential energy and am always told that this is wrong. According to wiki: "In physics, potential energy is the energy possessed by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors." Why do this...
I am not sure exactly what E = mc^2 means.
1. Does it simply means if we were able to convert mass into energy this is the amount of energy.
2. That mass and energy are different states of the same thing. An example would be water which can either be a solid (ice), a liquid (water) or a...
Using these equations I am about to prove that photons have a rest mass of zero (mathematically)
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E=hc/λ Photon Energy Equation
E2=(pc+mc2)2 Mass-Energy Equivalence with Momentum Equation
p=h/λ Momentum...
Homework Statement
Calculate the energy equivalent of the mass of an alpha particle.
alpha particle (amu) = 4.00150618 u
1 amu = 1.660566*10-27 kg
1 amu = 931.5020 MeV
alpha particle (kg) = 6.64465675 * 10-27 kg
Homework Equations
e = mc2
The Attempt at a Solution
931.5020 MeV *...
In the Wikipedia entry on mass-energy equivalence*, there is a reference to an elementary derivation of mass-energy equivalence in an article by Rohrlich (AJP 1990), which apparently expands on the original thought experiment by Einstein (ie observer in middle of moving train, light pulses...
Homework Statement
The diagram shows a proton moving with Ek of (0.178)(10-12)J towards a stationary nucleus X. The proton hits X and is absorbed.
The resulting nucleus splits into two alpha particles, which move off in the directions shown with equal Ek of (1.481)(10-12)J
1. Calculate the...
Simple algebra to find the strict mass–energy equivalence formula, and I can't do it!
find ((m^2)*(c^4)=(E^2)-(p^2*c^2)) from (E=m*c^2*y) (p=m*y*v)
(y=1/(1-(v^2/c^2))^(1/2))
Yeh i can find the m^2c^4 parts and the E^2 obvioulsy. but then i am stuck with E^2(v^2/c^2) when instead i want...
Hi.
I've seen a video by MinutePhysics that talked about the mass-energy equivalence equation,
usually known as E=mc^2.
It said that there is an extra part to it, and I didn't really understand what it meant.
(E^2)=((mc^2)^2)+((pc)^2) seems to be the full one (p being momentum)
So...
This really isn't a homework question per se, but I really don't want to post in the big boys' fora.
I am learning about basic modern physics at school, as the title suggests, but I am very confused on one matter. Take the tritium nucleus as an example.
If tritium nucleons are separate...
While I was looking up E=mc^{2}, I have learned such formula only applies to stationary objects and for kinetic object, the formula is this:
E_{r}=\sqrt{(m_{0}c^{2})^{2}+(pc)^{2}}
Where E_{r} is relativistic energy
and m_{0} is rest mass
In the formula, what is p and what is (pc)^{2}...
Hello All,
Let m be a mass, equivalent to energy E such, that E=mc^{2}.
Does it follow that c is the cosmic speed limit?
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To say the above with more words:
1) m is a mass
2) in some process, it is established that through...
Hello All,
is the following in principle, correct:
Scenario A:------------
1A) A box with mass M contains mass m, their weight is g(m+M)
2A) the mass m is (somehow) converted to energy E=mc^{2}
3A) at this moment, the box still has weight g(m+M)
Scenario B: ----------
1B) A box...
I've always been interested in Physics so have finally decided to do a Physics degree. I've been reading various things to help prepare myself and have just been reading about the laws of thermodynamics and mass-energy equivalence. As I'm reading through different articles about these subjects...
Pair-production is the event when a particle and anti-particle is created from a single photon. We don't see 2 or more photons participating in a single pair-production event. Further, it seems in all the events of energy-mass conversion, photons act independently.
Two or more photons can...
I was reading WikiPedia's entry on this, and there was one paragraph that surprised me:
E = mc2 has sometimes been used as an explanation for the origin of energy in nuclear processes, but mass–energy equivalence does not explain the origin of such energies. Instead, this relationship merely...
Homework Statement
My textbook is only confusing me further and I need to understand this for a presentation in front of the class! The chapter is entitled Mass-Energy Equivalence, with sub titles Relativistic Momentum and Relativistic Energy. I don't understand relativity, I'm reading the...
Einstein proposed a very simple derivation to E=mc^2 in 1940s which is well-known as Einstein’s box and a brief introduction is in
http://galileo.phys.virginia.edu/classes/252/mass_and_energy.html . If this event occurs in media instead of vacuum, the light speed should be u=c/n rather than c...
I'm curious about the famous formula, e=mc^2 . Since mass can be measured in any of several unit systems, shouldn't the formula read e\propto mc^2 ?
Thanks!
I was thinking just a moment ago and fragments of random knowledge and ideas gathered to make this question...
If I remember my college physics class correctly, an evidence of the mass-energy equivalence is that in an atom, the sum of the rest masses of the nucleons is greater than the rest...