A $0\mathrm{.}253-$nm photon collides with a stationary electron. After the collision, the electron moves

forward and the photon recoils backwards.

a$)$ Find the momentum of the electron. $($Ans: $5\mathrm{.}19$e$-24$ kg $$ m$/$s$)$

b$)$ Find the kinetic energy of the electron. $($Ans: $92\mathrm{.}5$ eV$)$