Catapults

BALLISTA

A trebuchet is a battle machine used to throw heavy projectiles, like boulders, at enemies.A trebuchet uses the energy of the falling counterweight to move the mechanical arm to launch the projectile.

TREBUCHET

The ballista is similar in principle to a crossbow, but much larger. It uses the energy stored in the twisted rope to launch darts, bolts and spears at enemies with high accuracy.

The mangonel uses the energy stored in the twisted rope in the torsion device to propel a projectile, such as rocks, into the air.Compared to the trebuchet which can shoot targets at the higher location, the mangonel was mainly used to shoot lower targets, such as breaking down walls.

MANGONEL

- You need something that can store energy (potential energy). This could be in the form of an elastic band, mechanical energy (twisting a rope or using your hands to push), etc.- Think of ways to increase the potential energy of your catapult, such as changing the length or weight of the mechanical arm. Experiment with different variables and methods!- Use the catapult models on the right as a guide. Which model is the most effective in achieving your goal?

CATAPULT BUILDING TIPS:

Information retrieved from: http://www.real-world-physics-problems.com/catapult-physics.html

HISTORY OF CATAPULTS

A catapult is a machine that stores energy then quickly releases this energy to fire a projectile. It is said to have originated in China around the 3rd and 4th Century BC.

It was used as a military machine in the Middle Ages in wars where tall structures (such as castles and walls) were involved. This was called siege warfare. Catapults were useful in hurling rocks and spears over long distances and tall heights.

Catapults take on various forms and function differently. Three main types are shown on the right. Click on the YouTube clips to see how they work!

Information retrieved from: http://medieval.stormthecastle.com/armorypages/catapults.htm