Start with a stationary rectangle. I assume you can determine which edge the bullet will strike. If it strikes a horizontal edge (constant Y), then reverse the Y-component of the trajectory; If it strikes a vertical edge (constant X), then reverse the X-component of the velocity.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.