If you are learning about medieval war machines, you can experience the subject firsthand by creating your own machine out of hardware materials, such as PVC pipe. You can create a catapult out of PVC pipe that can actually be used to hurl objects across a distance. When finished, you can invite friends over to see who can hurl an object the farthest.
Duct tape three PVC pipes into a triangle.
Repeat this process two more times until you have three triangles.
Place the triangles on a flat surface.
Tape two of the triangles together on one side. This will allow them to open up like a book.
Slide the third triangle in between the other two so that it lies flat on the table. Tape the whole structure together.
Place another PVC pipe into the farthest corner of the bottom triangle, taping it into place just at the corner. This will allow it to be secure while moving up and down freely.
Loop a bungee cord around the freely moving pipe, hooking the ends together.
Tape a plastic bowl to the end of the freely moving PVC pipe.
Place an object into the bowl, pull the freely moving pipe back to stretch the bungee cord, and release it to send the object flying.