A lever is simply a rigid beam that is free to rotate on a pivot. It's perfect for moving heavy things. It is a very useful simple machine. A lever is simply a rigid beam free to rotate on a pivot. It's perfect for moving heavy things. It is a very useful simple machine and you can find it everywhere. Good examples of levers include the swing, crowbar, fishing line, oars, wheelbarrows, and garden shovel. A lever is simply a rigid board or beam free to rotate on a pivot. It is perfect for lifting or moving heavy objects. It is a very useful simple machine and you can find it everywhere. Good examples of levers include the swing, crowbar, fishing line, oars, wheelbarrows, and garden shovel. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essayA lever is a simple machine consisting of a long beam attached to a pivot point (fulcrum) on which a load is attached and an effort force is applied. Levers work to reduce the amount of effort required to move a load, providing a mechanical advantage. Longer levers offer a much greater mechanical advantage. A lever is a machine that simplifies work and involves moving a load around a pin using force. Simply put, levers are machines used to increase strength. We call them "simple machines" because they only have two parts, the handle and the fulcrum. The lever handle is called the "arm" which is the part you push or pull on. The "fulcrum" is the point on which the lever turns or balances. In the case of the fork, the fulcrum is the fingers of the hand. Scissors are actually two levers put together. The toilet flush handle is commonly called a fixed lever. Take a quick look around you and see how many levers you can find. It is perfect for lifting or moving large, heavy objects. It is a simple machine and anyone can find it. Good examples of levers include the crowbar, seesaw, fishing line, oars, wheelbarrows, and garden shovel. Levers are one of the ordinary tools probably used in prehistoric times. Levers were first discovered around 260 BC by the Greek mathematician Archimedes. The axis of the lever is located between the load work off center of the lever. The largest load of effort is moved a small distance. Catapults have been an integral part of siege warfare since ancient times. Ancient catapults were one of the most effective weapons in siege warfare. Different types of catapults were used by the Greeks, Romans and Chinese. The first catapults were the first attempts to increase the range/power of a crossbow. Diodorus Siculus, a Greek historian, was the first to document the use of a mechanical catapult that fired arrows (ancient Ballista) in 399 BC. Catapults as we think of them were introduced to Europe during the Middle Ages. Catapults made their show in England in 1216 during the siege of Dover, the French crossed the Channel and were the first to use catapults on English soil. With warfare prevalent throughout Europe during the Middle Ages, the popularity of fortified castles and city walls increased significantly. This made catapults an essential element. Please note: this is just an example. Get a custom paper from our expert writers now. Get a Custom Essay Catapults were used to launch missiles (many different objects were used). These missiles were launched directly at the walls to cause maximum damage to the fortifications, or they were launched beyond the walls to besiege the population within the protective walls. Catapults were used for.