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Ballistics Experts
Ballistics is the field of mechanics concerned with the launching, flight behaviour and impact effects of projectiles, especially weapon munitions such as bullets, unguided bombs, rockets and the like; the science or art of designing and accelerating projectiles so as to achieve a desired performance. A ballistic body is a free-moving body with momentum, which can be subject to forces such as those exerted by pressurized gases from a gun barrel or a propelling nozzle, normal force by rifling, and gravity and air drag during flight. A ballistic missile is a missile that is guided only during the relatively brief initial phase of powered flight, with the trajectory subsequently governed by the laws of classical mechanics, in contrast to (for example) a cruise missile, which is aerodynamically guided in powered flight like a fixed-wing aircraft. History and prehistory The earliest known ballistic projectiles were stones, spears, and the throwing stick. The oldest evidence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trajectory
A trajectory or flight path is the path that an object with mass in motion follows through space as a function of time. In classical mechanics, a trajectory is defined by Hamiltonian mechanics via canonical coordinates; hence, a complete trajectory is defined by position and momentum, simultaneously. The mass might be a projectile or a satellite. For example, it can be an orbit — the path of a planet, asteroid, or comet as it travels around a central mass. In control theory, a trajectory is a time-ordered set of states of a dynamical system (see e.g. Poincaré map). In discrete mathematics, a trajectory is a sequence (f^k(x))_ of values calculated by the iterated application of a mapping f to an element x of its source. Physics of trajectories A familiar example of a trajectory is the path of a projectile, such as a thrown ball or rock. In a significantly simplified model, the object moves only under the influence of a uniform gravitational force field. This can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristotle
Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, and the arts. As the founder of the Peripatetic school of philosophy in the Lyceum (classical), Lyceum in Athens, he began the wider Aristotelianism, Aristotelian tradition that followed, which set the groundwork for the development of modern science. Little is known about Aristotle's life. He was born in the city of Stagira (ancient city), Stagira in northern Greece during the Classical Greece, Classical period. His father, Nicomachus (father of Aristotle), Nicomachus, died when Aristotle was a child, and he was brought up by a guardian. At around eighteen years old, he joined Plato's Platonic Academy, Academy in Athens and remained there until the age of thirty seven (). Shortly after Plato died, Aristotle left Athens and, at the request ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niccolò Tartaglia
Nicolo, known as Tartaglia (; 1499/1500 – 13 December 1557), was an Italian mathematician, engineer (designing fortifications), a surveyor (of topography, seeking the best means of defense or offense) and a bookkeeper from the then Republic of Venice. He published many books, including the first Italian translations of Archimedes and Euclid, and an acclaimed compilation of mathematics. Tartaglia was the first to apply mathematics to the investigation of the paths of cannonballs, known as ballistics, in his ''Nova Scientia'' (''A New Science'', 1537); his work was later partially validated and partially superseded by Galileo's studies on falling bodies. He also published a treatise on retrieving sunken ships. Personal life Nicolo was born in Brescia, the son of Michele, a dispatch rider who travelled to neighbouring towns to deliver mail. In 1506, Michele was murdered by robbers, and Nicolo, his two siblings, and his mother were left impoverished. Nicolo experienced further ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of China
The history of China spans several millennia across a wide geographical area. Each region now considered part of the Chinese world has experienced periods of unity, fracture, prosperity, and strife. Chinese civilization first emerged in the Yellow River valley, which along with the Yangtze basin constitutes the geographic core of the Chinese cultural sphere. China maintains a rich diversity of ethnic and linguistic people groups. The traditional lens for viewing Chinese history is the dynastic cycle: imperial dynasties rise and fall, and are ascribed certain achievements. This lens also tends to assume Chinese civilization can be traced as an unbroken thread many thousands of years into the past, making it one of the cradles of civilization. At various times, states representative of a dominant Chinese culture have directly controlled areas stretching as far west as the Tian Shan, the Tarim Basin, and the Himalayas, as far north as the Sayan Mountains, and as far south ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holmegaard
Until 1 January 2007, Holmegaard was a municipality ( Danish, '' kommune'') in Storstrøm County in the southern part of the island of Zealand (''Sjælland'') in south Denmark. The municipality covered an area of 66 km2, and had a total population of 7,442 (2005). Its last mayor was Søren Dysted, a member of the Social Democrats (''Socialdemokraterne'') political party. The main town and the site of its municipal council was the town of Fensmark. The municipality was created in 1966 when the following parishes were combined: Fensmark-Rislev Parish and Holme-Olstrup Parish. As the result of ("Municipality Reform") in 1970, Toksværd Parish was incorporated into Holmegaard municipality, and Rislev Parish was incorporated into Næstved municipality. Holmegaard municipality ceased to exist as the result of ''Kommunalreformen'' ("The Municipality Reform" of 2007). It was merged with existing Fladså, Fuglebjerg, Næstved Næstved () is a town in Næstved Municipa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamburg
Hamburg (, ; ), officially the Free and Hanseatic City of Hamburg,. is the List of cities in Germany by population, second-largest city in Germany after Berlin and List of cities in the European Union by population within city limits, 7th-largest in the European Union with a population of over 1.9 million. The Hamburg Metropolitan Region has a population of over 5.1 million and is the List of EU metropolitan areas by GDP, eighth-largest metropolitan region by GDP in the European Union. At the southern tip of the Jutland Peninsula, Hamburg stands on the branching River Elbe at the head of a estuary to the North Sea, on the mouth of the Alster and Bille (Elbe), Bille. Hamburg is one of Germany's three city-states alongside Berlin and Bremen (state), Bremen, and is surrounded by Schleswig-Holstein to the north and Lower Saxony to the south. The Port of Hamburg is Germany's largest and Europe's List of busiest ports in Europe, third-largest, after Port of Rotterdam, Rotterda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spear-thrower
A spear-thrower, spear-throwing lever, or ''atlatl'' (pronounced or ; Classical Nahuatl, Nahuatl ''ahtlatl'' ) is a tool that uses leverage to achieve greater velocity in Dart (missile), dart or javelin-throwing, and includes a Plain bearing, bearing surface that allows the user to store energy during the throw. It may consist of a shaft with a cup or a spur at the end that supports and propels the butt of the spear. It's usually about as long as the user's arm or forearm. The user holds the spear-thrower in one hand, gripping near the end farthest from the cup. The user puts the butt end of the spear, or dart, in the cup, or grabs the spur with the end of the spear. The spear is much longer than the thrower. The user holds the thrower at the grip end, with the spear resting on the thrower and the butt end of the spear resting in the thrower's cup. The user can hold the spear, with the index and thumb, with the same hand as the thrower, with the other fingers. The user reaches b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Throwing Stick
The throwing stick or throwing club is a wooden rod with either a pointed tip or a spearhead attached to one end, intended for use as a weapon. A throwing stick can be either straight or roughly boomerang-shaped, and is much shorter than the javelin. It became obsolete as Sling (weapon), slings and Bow (weapon), bows became more prevalent, except on the Australia, Australian continent, where the Indigenous Australians, native people continued refining the basic design. Throwing sticks shaped like returning boomerangs are designed to fly straight to a target at long ranges, their surfaces acting as airfoils. When tuned correctly they do not exhibit curved flight, but rather they fly on an extended straight flight path. Straight flight ranges greater than have been reported by historical sources as well as in recent research. Distribution The ancient Egyptians used throwing sticks to hunt small game and waterfowl, as seen in several wall paintings. The Eighteenth Dynasty of Egy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed-wing Aircraft
A fixed-wing aircraft is a heavier-than-air aircraft, such as an airplane, which is capable of flight using aerodynamic lift. Fixed-wing aircraft are distinct from rotary-wing aircraft (in which a rotor mounted on a spinning shaft generates lift), and ornithopters (in which the wings oscillate to generate lift). The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang gliders, variable-sweep wing aircraft, and airplanes that use wing morphing are all classified as fixed wing. Gliding fixed-wing aircraft, including free-flying gliders and tethered kites, can use moving air to gain altitude. Powered fixed-wing aircraft (airplanes) that gain forward thrust from an engine include powered paragliders, powered hang gliders and ground effect vehicles. Most fixed-wing aircraft are operated by a pilot, but some are unmanned or controlled remotely or are completely autonomous (no remote pilot). History Kites Kites were used approximately 2,800 years ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
