Presentation on theme: "Introduction: What is a catapult? A catapult is a machine that shoots objects into the air. It was often used as a weapon - to shoot large boulders at."— Presentation transcript:
Introduction: What is a catapult? A catapult is a machine that shoots objects into the air. It was often used as a weapon - to shoot large boulders at the enemy. Basically, its a large lever.
History of the Catapult Catapults were the first form of field artillery used by the Greeks. The word Catapult means shield piercer. The first catapults were based on the bow and arrow. They were called Ballista, and they shot spears.
History of the Catapult It was difficult to construct, so the Romans developed the Mangonel. It is the type of catapult that we are most familiar with. The catapult was slowly replaced by gunpowder artillery during the 14th and 15th centuries.
Trajectory / Launch Concepts Trajectory: the path a projectile makes through space under the action of given forces such as thrust, wind, and gravity.
A Simple Catapult: 18.5 cm 11 cm21.5 cm 16 cm
Fantastic Factfile: Machines A Machine is a simple device used to make work easier. There are six basic simple machines: An inclined plane is a slanted surface that increases the distance, but decreases the work. A ramp is an inclined plane. A wedge is a movable inclined plane. The blade of a knife is a wedge. A screw is an inclined plane wrapped around a bar. A corkscrew is a type of screw. A pulley consists of a wheel and a rope or string that is wrapped around it. Pulleys can change direction of a force as well as increase the mechanical advantage. A lever is a bar that pivots around a fulcrum. A crowbar is a type of lever. A wheel and axle is a cylindrical drum and wheel mounted on the same axle.
What is Force? A force is a push, pull, or lift. Effort force - the force applied to a machine Resistance force - the force that opposes the effort force (weight) Efficiency- the comparison of work output to work input Mechanical advantage - the number of times a machine multiplies the effort force
Conclusion A catapult is a machine that shoots objects into the air. It was often used as a weapon. It is a lever - one of the six types of machines. Machines make work easier.