I second @Ibix reply. The two particles have the same velocity (speed and direction) but energy and momentum are different and consequently wavelength and frequency.pellman said:The 4-momentum of a massless particle traveling in the z direction is (k, 0, 0, k). What is the significance of the value of k? It does not determine the speed since they always travel at light speed. If one particle has momentum (k, 0, 0, k) and another has (j, 0, 0, j) with j not equal to k, what is the physical difference between them?
4-momentum of a massless particle is a mathematical concept used in physics to describe the energy and momentum of a particle that has zero mass. It is composed of four components: energy, x-momentum, y-momentum, and z-momentum.
4-momentum of a massless particle is important because it allows us to understand and calculate the behavior of massless particles, such as photons, in different physical processes and interactions. It also plays a crucial role in the theory of relativity and quantum mechanics.
The 4-momentum of a massless particle is calculated using the equation P = (E, px, py, pz) = (hf/c, hf/c, hf/c, hf/c), where h is Planck's constant, f is the frequency of the particle, and c is the speed of light.
For a massless particle, the energy (E) and the magnitude of momentum (p) are directly proportional, meaning that as the energy increases, the magnitude of momentum also increases. This relationship is described by the equation E = pc, where c is the speed of light.
Yes, a massive particle can have 4-momentum. However, unlike for massless particles, the energy and momentum of a massive particle are not directly proportional and are given by the equation E^2 = (pc)^2 + (mc^2)^2, where m is the mass of the particle and c is the speed of light.