\(P _{ i }= P _{ f }\) (By linear momentum conservation)
\(0=\frac{ h }{\lambda}- Mv = V _{ Recoil }=\frac{ h }{\lambda M }.....(i)\)
And \(\Delta E =\frac{ hc }{\lambda}=\frac{ hc }{\lambda M } \times M \Rightarrow McV _{ Recoil }\)
\(V _{ Recoil }=\frac{\Delta E }{ Mc }=\frac{13.06 \times 1.6 \times 10^{-19}}{1.67 \times 10^{-27} \times 3 \times 10^{8}}=4.17 \,m / sec\)