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Answer: The mass of a photon is essentially zero,
<1×10−18 eVAnswer: The rest mass, or invariant mass, of a photon is zero, since it travels at the speed of light. Since it has energy, it does have an associated mass, according to the Theory of Relativity; however, different types of electromagnetic radiations (photons) have different energies in this case, and therefore different masses.
Wiki User
∙ 13y ago
Wiki User
∙ 14y agoThere's a kind of a duality here. Photons are supposed to be massless, because otherwise they wouldn't be able to reach lightspeed (according to Newtons Law F=ma, if it applies, because to accelerate a photon to lightspeed would require imense forces).
On the other hand it's proven they have some kind of mass because scientist through several experiments have been able to see a photon transfer momentum to other particles (p = mv => momentum = mass * velocity).
Some other equations that have mass of a photon in them:
Since p = mv and p = h/λ, then h/λ = mv, where h is Plank's constant, and λ the wavelength of the photon.
KE = 0.5mv2, where KE is kinetic energy.
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∙ 12y agosame as elektron with velocity 0
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What is the energy carried by a photon in relativistic physics?
It's proportional to the frequency of the photon ... 6.63 x 10-34 joule per Hz.
What is the mass of moving photon?
the mass of a photon is zero
What is the mass of one photon?
mass of the proton is 0. Answer 2 But the question asked about photons, not protons. The mass of a photon is also 0, though the mass of a proton is not!
Why is the energy of a photon greater than that of an electron?
It does not. A photon has no rest mass an electron has mass and therefore more energy
How much mass does a photon of light have?
"it is so light i cant be measured"This is 'sort of' right. The mass of a photon is a difficult thing to talk about because we tend to think of there being one type of mass but, in physics, there are at least two types. One is the invariant mass and the other is the relativisticmass. These two masses are different - even for the same particle - if the particle is being observed from a reference frame whose velocity is not that of the reference frame of the particle itself.We're used to the equation E = mc², but that is really only a part of the story. The full equation is E² = m²0c⁴ + p²c² ... and this contains a component related to motion: p (for momentum) is included in the second term of the full equation. The subscript 0 in the first term denotes the first type of mass: invariant or rest mass.We know that momentum is a property that depends on mass as well as velocity: p = mv (using bold letters here to denote vector quantities: in the energy-mass equivalence relation, we use only scalar quantities, since energy is a scalar quantity and has no direction). So if m = 0kg, then p = 0 kgms⁻¹. The same is true if |v| (or p, the absolute value of v) is 0 ms⁻¹.So now we get to the important bit. When dealing with photons, we have - in the full equation - a term for the invariantmass (also known as the rest mass): this is the m0²c⁴ bit. We also have a term relating to the relativistic mass: this is the p²c² bit. And the total eneery of a photon is given by the sum of these two terms.When a photon has no speed (this is the absolute value of velocity), it has no rest mass. so the first term (m0²c⁴) is redundant. But when it is moving, this term remains unaffected. When it is stationary, the second term is also redundant. But when the photon is moving, this term now assumes relevance. Photon moves, and momentum is acquired. No photon, incidentally, can exist at rest.The energy of a photon is given, then, by the square root of the product of the square of its momentum and the speed of light squared. Thus: E = (p²c²)½ which means E = pc. If we know the actual speed of the photon through a given medium, then we can calculate the relativistic mass of the photon by substituting p =mv in this equation, giving E = mvc.This - when divided through by vc - gives E/vc = m, which is the relativistic mass of the photon. This curve is akin to the y = 1/x curve and so, as speed increases, mass actually decreases. But, because of the c multiplier, this decrease is probably quite insignificant.Other than this somewhat mathematical treatment given here, I cannot go more specific because of the absence of any specific data on speeds and energies of photons.To recap, then:1- The invariant or rest mass of a photon is 0 kg. Always.2- The relativistic mass if a photon is given by dividing the energy of the photon by the product of the speed of light in a vacuum and its actual velocity in the medium through which it is being propagated. This is a mass that decreases slightly as speed increases, but probably not by any measurableamount.
WHAT According Einstein is the relativistic mass of light?
Any object has two masses associated.What is sometimes called the rest mass, or invariant mass, for the photon (piece of light), is zero. Its relativistic mass is equal to its energy divided by c squared.
What is the energy carried by a photon in relativistic physics?
It's proportional to the frequency of the photon ... 6.63 x 10-34 joule per Hz.
What is the mass of moving photon?
the mass of a photon is zero
What is the plot mass of photon?
the photon has got 0 rest mass .and plot mass means? not knowing..
If the mass of an object approaches infinity as the object approaches the speed of light why doesn't light have infinite mass?
The statement that photons have zero mass refers to what is traditionally known as the "rest mass" - nowadays simply called the "mass", i.e., the one mass that all observers will agree upon.On the other hand, the "relativistic mass" is positive - and the ratio between this positive relativistic mass and the zero rest mass is infinite.
mass of photon?
Photons have no mass.
What is the smallest in mass?
A photon.
What is the mass of one photon?
mass of the proton is 0. Answer 2 But the question asked about photons, not protons. The mass of a photon is also 0, though the mass of a proton is not!
Why is the energy of a photon greater than that of an electron?
It does not. A photon has no rest mass an electron has mass and therefore more energy
What subatomic particles have a mass of 0?
The photon. This refers to the "rest mass"; since the photon has energy, it also has an associated mass. But the "rest mass" or "invariant mass" is zero.
What is the mass of a photon in motion?
A photon is a massless particle, meaning it has no rest mass. Its mass is zero, but it does have energy and momentum.
Can a mass be zero outside the earth?
Universality is a fundamental principle in physics - the same laws of physics apply everywhere at all times. So if the mass of something on earth is zero (such as the rest mass of a photon), then the mass will be zero everywhere in the universe, disregarding the effects of relativistic mass. Do not confuse mass with weight - mass is invariable - it is the same everywhere. Weight, however, diminishes in proportion to the square of the distance you travel away from the center of planet earth.
