The Trebuchet

The word trebuchet comes from the french word trébuchet. The older versions of trebuchets, called "traction trebuchets" had pulling men rather than a counterweight. The counterweight trebuchet (shown above), was meant to fire projectiles over castle walls, thus launching projectiles high into the air.

The trebuchet is loaded by pulling the beam back and keeping the beam restrained, while a projectile is loaded into the pouch, located at the end of the sling attached to the beam. The beam is then released, pulled by the counterweight, and causing the sling to swing around above the moving beam. One of the strings of the sling that is attached to the finger at the end of the beam is detached, letting the projectile's inertia push the projectile forward.

The heavier the counterweight is, the further the projectile will fly. The weight (gravity) makes an object fly in this case.

   

The trebuchet was mainly used to haul rocks and other projectiles into enemy castles and fortresses. The advantage of the trebuchet is that you can launch just about anything, since you load projectiles on a pouch. A few common items might be rocks, burning wood, and dead or sick cows.

Also, it can launch things with accuracy and consistency, as long as the counterweight remains the same. The heavier the counterweight is, the farther and higher the projectile will fly.

Unlike the mangonel, trebuchets launch objects far and high. They were used to haul objects like dead cows and fire balls inside of a castle or a fortress.

Image source: http://www.real-world-physics-problems.com/catapult-physics.html