My class is doing a robotics assignment and i have to write a paragraph explaining how my catapult meets the needs of my research field. my research field is past present future.

Both catapults and ballistas work by storing tension either in twisted ropes or in a flexed piece of wood (in the same way an archery bow does, but on a larger scale). A trebuchet tends to be easier to build because it consists simply of a pivoting beam and a counterweight that rotates the beam through an arc.