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Question
Calculate the momentum of a photon of light of wavelength 500 nm.
(Use h = 6.63 × 10-34J-s = 4.14 × 10-15 eV-s, c = 3 × 108 m/s and me = 9.1 × 10-31kg)
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Solution
Given :-
Wavelength of light, λ = 500 nm
Planck's constant, `h = 6.63 xx 10^-34 "J-s"`
Momentum of a photon of light ,
`p = h/ λ`
`= (6.63 xx 10^-34)/(500 xx 10^-9)`
`= 6.63/5 xx 10^-27`
`= 1.326 xx 10^-27`
`= 1.33 xx 10^-27 "kg"-m"/"s`
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