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Neeraj
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Even if a beam of light strikes a reflective surface at an angle 'A', the change in momentum should be 2mc, P=2IcosA/C but I find it P= 2Icos^2(A)/C.
Where did you see this?...I believe you are correctNeeraj said:Even if a beam of light strikes a reflective surface at an angle 'A', the change in momentum should be 2mc, P=2IcosA/C but I find it P= 2Icos^2(A)/C.
Which one? I believe speed of light is constant in every frame we presume. I found it in a book.hutchphd said:Where did you see this?...I believe you are correct
Here we require the change in momentum to find the force and then the pressure, and since we can't associate mass to photons, mass energy equivalence can be used to replace mass (p.s. It was explained in photoelectric effect to find out radiation pressure)I don't remember the exact source, I just wanted to confirm if I am right or not.hutchphd said:If the velocity of the surface is large (near c) there will also be an appreciable effect from the Doppler shift, so the result will need modification. If you quote a result it is good form to provide the source (I.e. which book..there are quite a few!).
Also you say p=mc ...what is m? This is not correct.
If you can check, I can send an image on how they derived it.Neeraj said:Here we require the change in momentum to find the force and then the pressure, and since we can't associate mass to photons, mass energy equivalence can be used to replace mass (p.s. It was explained in photoelectric effect to find out radiation pressure)I don't remember the exact source, I just wanted to confirm if I am right or not.
If you are using relativistic mass (*shudder*) then mc^2 = E = pc. Divide by c to get mc = E/c = pNeeraj said:If you can check, I can send an image on how they derived it.
Photons are massless so in order to avoid the term m we can use debroglie's dual nature theory or whatever you just saidjbriggs444 said:If you are using relativistic mass (*shudder*) then mc^2 = E = pc. Divide by c to get mc = E/c = p
The equation for calculating light reflection momentum is P=2Icos^2(A)/C, where P is the momentum, I is the intensity of the light, A is the angle of incidence, and C is the speed of light.
The angle of incidence, denoted by A in the equation, is directly related to the light reflection momentum. As the angle of incidence increases, the light reflection momentum decreases.
Intensity, denoted by I in the equation, is a measure of the amount of light energy per unit area. It affects the overall magnitude of the light reflection momentum, with higher intensities resulting in greater momentum.
Yes, the speed of light, denoted by C in the equation, is a constant that plays a significant role in determining the light reflection momentum. As the speed of light increases, the momentum also increases.
Light reflection momentum is a useful concept in understanding the behavior of light and its interactions with different surfaces. It can be applied in various fields such as optics, astronomy, and material science to study the properties of light and its impact on different materials.