Momentum of a photon is
Correct answer: C. hf/c
- A. 0
- B. a
- C. hf/c
- D. mv
Explanation
Photons have their momentum found from de Broglie's equation P=h/lambda, and "lambda" can be found by dividing f(speed of light) by "f" (frequency), so option C stands true.The momentum of a photon can be calculated using the equation:p = h/λwhere p is the momentum of the photon, h is Planck's constant, and λ is the wavelength of the photon.We can also use the relationship between wavelength and frequency:c = λfwhere c is the speed of light and f is the frequency of the photon.Rearranging the above equation, we get:λ = c/fSubstituting this value of λ in the expression for momentum, we get:p = h/(c/λ)p = h/(c/(c/f))p = hf/cSo the momentum of a photon can be expressed as hf/c, where h is Planck's constant, f is the frequency of the photon, and c is the speed of light.
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Classical physics cannot explain blackbody radiation and related observations, leading to Planck’s quantum theory, in which energy is emitted or absorbed in discrete packets. Photons provide the particle model of light, with energy and momentum linked to frequency and wavelength, including the photoelectric effect and its threshold frequency.
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