question_answer

Find the wavelength of a photon whose energy is equal to 931.5 MeV (MeV is million electro volt and \[\text{1eV}=\text{1}.\text{6}0\text{2}\times \text{1}{{\text{0}}^{-19}}J\])

Answer:

\[E=931.5\text{ }Mev=931.5\times {{10}^{6}}\times 1.602\times {{10}^{19}}J\] Applying: \[E=\frac{hc}{\lambda }:931.5\times {{10}^{6}}\times 1.602\times {{10}^{-19}}\] \[=\frac{6.625\times {{10}^{-34}}\times 3\times {{10}^{8}}}{\lambda }\] \[\Rightarrow \]\[\lambda =\frac{6.625\times {{10}^{-34}}\times 3\times {{10}^{8}}}{931.5\times {{10}^{6}}\times 1.602\times {{10}^{-19}}}\] \[=13.334\times {{10}^{-16}}m\]