Monochromatic light of wavelength 632.8 nm is produced by a helium-neon laser. The power emitted is 9.42 mW.
Find the energy and momentum of each photon in the light beam,

Explanation

Here, `lamda=632.8nm=632.8xx10^(-9)m`,
`P=9.42mW=9.42xx10^(-3)W`
Energy of each photon in the light beam is
`E=(hc)/(lamda)=(6.62xx10^(-34)xx3xx10^(8))/(632.8xx10^(-9))=3.14xx10^(-19J)`
Momentum of each photon in the light beam is
`P=(h)/(lamda)=(6.62xx10^(-34))/(632.8xx10^(-9))1.05xx10^(-27)kgms^(-1)`