Question

Calculate the mass of a photon whose wave length is $3.6\mathring{A}$.

Answer 1

Momentum $p=\frac{h}{\lambda }=mv$

$\therefore m=\frac{h}{\lambda V}=\frac{6.627\times {10}^{-34}}{3.6\times {10}^{10}\times 3\times {10}^8}=6.138\times {10}^{-33}kg$

$\therefore$ Mass of photon with $\lambda =3.6\stackrel{o}{A}=6.138\times {10}^{-33}kg$