1. CATAPULTS and TREBUCHETS October 18, 2005

2. WHAT ARE CATAPULTS AND TREBUCHETS? Ancient ballistic weapons used in siege warfare. Many large catapults can launch a projectile 150 – 300 meters. That’s almost a quarter of a mile!!!

3. Ancient Greek Engineering In 399 B.C. Dionysius the Elder, ruler of the Greek colony of Syracuse in Sicily, prepared his city for a long war with Carthage by undertaking search and development program. Syracuse Carthage

4. Dionysius of Alexandria Repeating Catapult

5. Greek Crossbow

6. Middelaldercentret Reconstruction of a late 14 th century Danish environment in Denmark.

7. HOW DO THEY WORK? Some catapults work by storing tension either in twisted ropes or a fixed piece of wood. Trebuchets work with a pivoting beam and a counterweight.

8. WHAT’S THE MATH? An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.unless acted upon by an unbalanced force NEWTON’S FIRST LAW OF MOTION

9. MORE MATH! A projectile has Horizontal and Vertical velocity and acceleration. The projectile motion equations for average velocity are: x = x 0 + v av · t y = y 0 + v av · t – 1/2 · g · t 2 Velocity is the change is distance over time. Acceleration is the rate of change in velocity.