Question 130
The hero of a cartoon faces his arch-enemy once more and needs to deliver his famous Reflective Ray strike. In the square in the figure below, the ray must, starting from $F$, bounce exactly once off each of the sides $CD, AD$ and $AB$, in this order, before hitting the enemy at position $E$. Whenever the ray bounces off one of the sides of the square, the angle of incidence equals the angle of exit, as shown in the figure on the right. Knowing that $BE=EF=FC=2~\mathrm{m}$ and that the ray travels at $1~\mathrm{m}/\mathrm{s}$, determine the time elapsed between the firing of the ray at $F$ and its arrival at point $E$.
