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Couillard
A trebuchet (french: trébuchet) is a type of catapult that uses a long arm to throw a projectile. It was a common powerful siege engine until the advent of gunpowder. The design of a trebuchet allows it to launch projectiles of greater weights and further distances than that of a traditional catapult. There are two main types of trebuchet. The first is the traction trebuchet, or mangonel, which uses manpower to swing the arm. It first appeared in China in the 4th century BC. Carried westward by the Avars, the technology was adopted by the Byzantines in the late 6th century AD and by their neighbors in the following centuries. The later, and often larger and more powerful, counterweight trebuchet, also known as the counterpoise trebuchet, uses a counterweight to swing the arm. It appeared in both Christian and Muslim lands around the Mediterranean in the 12th century, and was carried back to China by the Mongols in the 13th century. Etymology and terminology It is un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trebuchet2
A trebuchet (french: trébuchet) is a type of catapult that uses a long arm to throw a projectile. It was a common powerful siege engine until the advent of gunpowder. The design of a trebuchet allows it to launch projectiles of greater weights and further distances than that of a traditional catapult. There are two main types of trebuchet. The first is the traction trebuchet, or mangonel, which uses manpower to swing the arm. It first appeared in China in the 4th century BC. Carried westward by the Avars, the technology was adopted by the Byzantines in the late 6th century AD and by their neighbors in the following centuries. The later, and often larger and more powerful, counterweight trebuchet, also known as the counterpoise trebuchet, uses a counterweight to swing the arm. It appeared in both Christian and Muslim lands around the Mediterranean in the 12th century, and was carried back to China by the Mongols in the 13th century. Etymology and terminology It is unce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trebuchet Castelnaud
A trebuchet (french: trébuchet) is a type of catapult that uses a long arm to throw a projectile. It was a common powerful siege engine until the advent of gunpowder. The design of a trebuchet allows it to launch projectiles of greater weights and further distances than that of a traditional catapult. There are two main types of trebuchet. The first is the traction trebuchet, or mangonel, which uses manpower to swing the arm. It first appeared in China in the 4th century BC. Carried westward by the Pannonian Avars, Avars, the technology was adopted by the Byzantine Empire, Byzantines in the late 6th century AD and by their neighbors in the following centuries. The later, and often larger and more powerful, counterweight trebuchet, also known as the counterpoise trebuchet, uses a counterweight to swing the arm. It appeared in both Christian and Muslim lands around the Mediterranean in the 12th century, and was carried back to China by the Mongols in the 13th century. Etymolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catapult
A catapult is a ballistic device used to launch a projectile a great distance without the aid of gunpowder or other propellants – particularly various types of ancient and medieval siege engines. A catapult uses the sudden release of stored potential energy to propel its payload. Most convert tension or torsion energy that was more slowly and manually built up within the device before release, via springs, bows, twisted rope, elastic, or any of numerous other materials and mechanisms. In use since ancient times, the catapult has proven to be one of the most persistently effective mechanisms in warfare. In modern times the term can apply to devices ranging from a simple hand-held implement (also called a "slingshot") to a mechanism for launching aircraft from a ship. The earliest catapults date to at least the 7th century BC, with King Uzziah, of Judah, recorded as equipping the walls of Jerusalem with machines that shot "great stones". Catapults are mentioned in Yajurv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mangonel
The mangonel, also called the traction trebuchet, was a type of trebuchet used in Ancient China starting from the Warring States period, and later across Eurasia by the 6th century AD. Unlike the later counterweight trebuchet, the mangonel operated on manpower pulling cords attached to a lever and sling to launch projectiles. Although the mangonel required more men to function, it was also less complex and faster to reload than the torsion-powered onager which it replaced in early Medieval Europe. It was replaced as the primary siege weapon in the 12th and 13th centuries by the counterweight trebuchet. A common misconception about the mangonel is that it was a torsion siege engine. Etymology ''Mangonel'' is probably derived from the Greek ''mangana'', "a generic term for construction machinery." It could also be derived from ''mangon'', a French hard stone found in the south of France. In Latin it is called a ''manganum'', in French a ''manganeau'', and in English a ''mang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force
A force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. The concept of force makes the everyday notion of pushing or pulling mathematically precise. Because the Magnitude (mathematics), magnitude and Direction (geometry, geography), direction of a force are both important, force is a Euclidean vector, vector quantity. The SI unit of force is the newton (unit), newton (N), and force is often represented by the symbol . Force plays an important role in classical mechanics. The concept of force is central to all three of Newton's laws of motion. Types of forces often encountered in classical mechanics include Elasticity (physics), elastic, frictional, Normal force, contact or "normal" forces, and gravity, gravitational. The rotational version of force is torque, which produces angular acceleration, changes in the rotational speed of an object. In an extended body, each part often applies forces on the adjacent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Advantage
Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the ''law of the lever.'' Machine components designed to manage forces and movement in this way are called mechanism (engineering), mechanisms. An ideal mechanism transmits power without adding to or subtracting from it. This means the ideal machine does not include a power source, is frictionless, and is constructed from rigid bodies that do not deflect or wear. The performance of a real system relative to this ideal is expressed in terms of efficiency factors that take into account departures from the ideal. Levers The lever is a movable bar that pivots on a wikt:fulcrum, fulcrum attached to or positioned on or across a fixed point. The lever operates by applying forces at different distances from the fulcrum, or pivot. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lever
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '' fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is divided into three types. Also, leverage is mechanical advantage gained in a system. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever. As such, the lever is a mechanical advantage device, trading off force against movement. Etymology The word "lever" entered English around 1300 from Old French, in which the word was ''levier''. This sprang from the stem of the verb ''lever'', meaning "to raise". The verb, in turn, goes back to the Latin ''levare'', itself from the adjective ''levis'', meaning "light" (as in "not heavy") ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axle
An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type axle is referred to as a '' spindle''. Terminology On cars and trucks, several senses of the word ''axle'' occur in casual usage, referring to the shaft itself, its housing, or simply any transverse pair of wheels. Strictly speaking, a shaft which rotates with the wheel, being either bolted or splined in fixed relation to it, is called an ''axle'' or ''axle shaft''. However, in looser usage, an entire assembly including the surrounding axle housing (typically a casting) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sling (weapon)
A sling is a projectile weapon typically used to throw a blunt projectile such as a stone, clay, or lead " sling-bullet". It is also known as the shepherd's sling or slingshot (in British English). Someone who specializes in using slings is called a slinger. A sling has a small cradle or ''pouch'' in the middle of two retention cords. A projectile is placed in the pouch. There is a loop on the end of one side of the retention cords. Depending on the design of the sling, either the middle finger or the wrist is placed through a loop on the end of one cord, and a tab at the end of the other cord is placed between the thumb and forefinger. The sling is swung in an arc, and the tab released at a precise moment. This action releases the projectile to fly to the target. The sling is much more than merely an extension of a human arm. By its double-pendulum kinetics, the sling enables stones (or spears) to be thrown much further than they could be by hand alone. The sling is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Power
Human power is work or energy that is produced from the human body. It can also refer to the power (rate of work per time) of a human. Power comes primarily from muscles, but body heat is also used to do work like warming shelters, food, or other humans. World records of power performance by humans are of interest to work planners and work-process engineers. The average level of human power that can be maintained over a certain duration of time is interesting to engineers designing work operations in industry. Human-powered transport includes bicycles, rowing, skiing and many other forms of mobility. Human-powered equipment is occasionally used to generate, and sometimes to store, electrical energy for use where no other source of power is available. These include the Gibson girl survival radio, wind-up or (clockwork) radio and pedal radio. Available power Normal human metabolism produces heat at a basal metabolic rate of around 80 watts. During a bicycle race, an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potential Energy
In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. Common types of potential energy include the gravitational potential energy of an object, the elastic potential energy of an extended spring, and the electric potential energy of an electric charge in an electric field. The unit for energy in the International System of Units (SI) is the joule, which has the symbol J. The term ''potential energy'' was introduced by the 19th-century Scottish engineer and physicist William Rankine, although it has links to Greek philosopher Aristotle's concept of Potentiality and Actuality, potentiality. Potential energy is associated with forces that act on a body in a way that the total work done by these forces on the body depends only on the initial and final positions of the body in space. These forces, that are called Conservative force, ''conservative forces'', can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
