E=pc
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Re: E=pc
Since p in this question is in reference to momentum which is equal to mass times velocity, I think this formula can only be used for particles that have mass. I think photons are considered massless particles, thus excluding them here.
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Re: E=pc
Hi,
I believe we use E=pc when the momentum of the photon is given in the question. In E=pc, E is the energy of a photon, p is the momentum of the photon, and c is the speed of light. As someone said above, I agree with using the formula for particles that have mass.
I believe we use E=pc when the momentum of the photon is given in the question. In E=pc, E is the energy of a photon, p is the momentum of the photon, and c is the speed of light. As someone said above, I agree with using the formula for particles that have mass.
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Re: E=pc
It can be used for particles because it uses momentum, which is mass times velocity. This equation can help you find the energy of an electron, but not a photon since they do not have a defined mass.
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Re: E=pc
Hi! We would use the equation (E=pc) when the question mentions particles mass and velocity. However, we use another equation (E=hv) for questions that gives you the photon’s frequency or wavelength.
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Re: E=pc
Hi! We can use this equation for particles, such as electrons, protons, neutrons, etc., therefore something that has a mass and velocity (particle qualities). However, we can use this for photons as well to calculate their momentum! We cannot use the mass and velocity of a photon to solve, as a photon does not have a mass, so we would first calculate the energy per photon using E=hv. After we have this we can divide this by the speed of light, so plugging the value for E into the E=pc equation to find the momentum of a photon. Hope this was helpful!
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Re: E=pc
Hi,
This equation only applies to particles with mass because p=momentum=mass*velocity. This equation would not be used to calculate the energy of a photon, however, because photons are massless particles. That is why for photons we use E=hv.
This equation only applies to particles with mass because p=momentum=mass*velocity. This equation would not be used to calculate the energy of a photon, however, because photons are massless particles. That is why for photons we use E=hv.
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Re: E=pc
I think the formula e = pc is only relevant when a mass is involved, because momentum is represented by p in the equation, and momentum is calculated as mass times velocity. This would mean that photons could not be applied to this formula.
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Re: E=pc
The equation E= pc is only used for particles with mass. Thus it wouldn't be used for photons because they have a negligible mass. You would use the equation E=hv using the frequency of the photon. So any particle with mass can use the E = pc equation!
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Re: E=pc
E = pc is used for particles as it includes momentum which equates to the particles mass times its velocity. Since photons are massless particles, you would instead use the equation E = hv to calculate the energy of a photon.
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Re: E=pc
I believe we use this when we are given mass and velocity and asked for the energy. Or any combination of two of those and missing one variable.
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