In this activity, students students will construct catapult and trebuchet (15th century military engine used for hurling heavy weapons and rocks) models using K'nex materials as well as wood and PVC pipe. While engaged in this activity, students learn about concepts such as levers, inertia, counterweights, friction and more. Teams of students will test their creations and skills to see which can hit targets at different distances and also knock objects off of a large castle cutout with the greatest accuracy.