Good day. The trebuchet is a straightforward application of conservation of energy and momentum. The counterweight drops, converting potential energy into kinetic energy that drives the arm. That kinetic energy is then transferred to the projectile, which follows a ballistic trajectory governed by the same equations we use for modern projectiles—gravity pulls it down, air resistance slows it, and the launch angle determines range. In short, yes, the physics of those medieval machines matches the principles we now formalize in projectile motion.

The optimal arm ratio—long arm to short arm—usually falls around 1.7 to 1.8 for maximum range. That gives the lever a good balance between torque and velocity. The counterweight mass should be roughly five to six times the projectile mass; that ratio delivers enough energy while keeping the arm speed manageable. Historical accounts match those figures, so your manuscripts are likely consistent with what we now calculate.

I’ve skimmed the old treatises on timber used in siege engines. The most cited ones are the “Treatise on Siege Mechanics” by Master Albrecht and the “Wood and War” essay by Bishop Leofric. Both note that oak and ash are preferred because of their high modulus of rupture and good toughness. The manuscripts suggest a maximum allowable stress of about 30 MPa for the arm; that’s consistent with modern calculations for long‑armed mechanisms. Cross‑checking those figures with your notes should confirm the wood‑dependent variance you mentioned.