Halloween Physics Fun!

I am so excited for my Grade 12 Physics class tomorrow for Halloween!  Any chance I get to work with shooting targets I'll take.  In Grade 11 my students launched "Angry Birds" (balloons filled with flour) at Pig Targets with their projectile launchers.
This week we've been working on Hooke's Law and Elastic Potential Energy.  The Grade 12s got to design their own launcher (only restrictions were it must be student-made in the classroom and had to obey Hooke's Law - they had to test that!).  On Halloween we're going to be shooting zombies in class!  They're such great kids they deserve a fun day and maybe some bonus marks if they win: