Question

the dynamic mass of a photon of wavelength (lambda) is?

Answer 1

As we know that E=mc^2 and E=hf by comparing both sides we have mc^2=hf , m=hf/c^2 , m=hf/cc,

as v=fλ also c=fλ, 1/λ=f/c

putting value of f/c in above formula m=hf/cc m=h/cλ

Answer is m=h/cλ