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Ricochet (Jo Jo Zep
A ricochet ( ; ) is a rebound, bounce, or skip off a surface, particularly in the case of a projectile. Most ricochets are caused by accident and while the force of the deflection decelerates the projectile, it can still be energetic and almost as dangerous as before the deflection. The possibility of ricochet is one of the reasons for the common firearms safety rule "Never shoot a bullet at a flat, hard surface." Ricochets can occur with ''any'' caliber, but short or round ricocheting bullets may not produce the audible whine caused by tumbling irregular shapes. Ricochets are a hazard of shooting because, for as long as they retain sufficient velocity, ricocheting bullets or bullet fragments may cause collateral damage to animals, objects, or even the person who fired the shot. Variables Ricochets occur when a bullet or bullet fragment is deflected by an object rather than penetrating and becoming embedded in that object. Ricochet behavior may vary with bullet shape, bullet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMMWV Tracer Fire Dark
The High Mobility Multipurpose Wheeled Vehicle (HMMWV; colloquial: Humvee) is a family of Military light utility vehicle, light, four-wheel drive, Military vehicle#Military trucks, military trucks and utility vehicles produced by AM General. It has largely supplanted the roles previously performed by the Willys MB, original jeep, and others such as the Vietnam War-era M151 ¼-ton 4×4 utility truck, M151 jeep, the Gama Goat, M561 "Gama Goat", their M718A1 and M792 ambulance versions, the Commercial Utility Cargo Vehicle, and other light trucks. Primarily used by the United States Armed Forces, United States military, it is also used by numerous other countries and organizations and even in civilian adaptations. The Humvee saw widespread use in the Gulf War of 1991, where it navigated the treacherous desert terrain; this usage helped to inspire civilian Hummer versions. The vehicle's original unarmored design was later seen to be inadequate. The vehicle was found to be particular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basketball
Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular Basketball court, court, compete with the primary objective of #Shooting, shooting a basketball (ball), basketball (approximately in diameter) through the defender's hoop (a basket in diameter mounted high to a Backboard (basketball), backboard at each end of the court, while preventing the opposing team from shooting through their own hoop. A Field goal (basketball), field goal is worth two points, unless made from behind the 3 point line, three-point line, when it is worth three. After a foul, timed play stops and the player fouled or designated to shoot a technical foul is given one, two or three one-point free throws. The team with the most points at the end of the game wins, but if regulation play expires with the score tied, an additional period of play (Overtime (sports), overtime) is mandated. Players advance the ball by bouncing it while walking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Air Weapons Station China Lake
Naval Air Weapons Station (NAWS) China Lake is a large military installation in California that supports the research, testing and evaluation programs of the United States Navy. It is part of Navy Region Southwest under Commander, Navy Installations Command, and was originally known as Naval Ordnance Test Station (NOTS). The installation is located in the Western Mojave Desert region of California, approximately north of Los Angeles. Occupying land in three counties – Kern, San Bernardino, and Inyo – the installation's closest neighbors are the city of Ridgecrest and the communities of Inyokern, Trona, and Darwin. China Lake is the United States Navy's largest single landholding, representing 85% of the Navy's land for weapons and armaments research, development, acquisition, testing and evaluation (RDAT&E) use and 38% of the Navy's land holdings worldwide. In total, its two ranges and main site cover more than , an area larger than the state of Rhode Island. As of 2010, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetry
Symmetry (from grc, συμμετρία "agreement in dimensions, due proportion, arrangement") in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, "symmetry" has a more precise definition, and is usually used to refer to an object that is invariant under some transformations; including translation, reflection, rotation or scaling. Although these two meanings of "symmetry" can sometimes be told apart, they are intricately related, and hence are discussed together in this article. Mathematical symmetry may be observed with respect to the passage of time; as a spatial relationship; through geometric transformations; through other kinds of functional transformations; and as an aspect of abstract objects, including theoretic models, language, and music. This article describes symmetry from three perspectives: in mathematics, including geometry, the most familiar type of symmetry for many people; in science and nature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inelastic Collision
An inelastic collision, in contrast to an elastic collision, is a collision in which kinetic energy is not conserved due to the action of internal friction. In collisions of macroscopic bodies, some kinetic energy is turned into vibrational energy of the atoms, causing a heating effect, and the bodies are deformed. The molecules of a gas or liquid rarely experience perfectly elastic collisions because kinetic energy is exchanged between the molecules' translational motion and their internal degrees of freedom with each collision. At any one instant, half the collisions are – to a varying extent – inelastic (the pair possesses less kinetic energy after the collision than before), and half could be described as “super-elastic” (possessing ''more'' kinetic energy after the collision than before). Averaged across an entire sample, molecular collisions are elastic. Although inelastic collisions do not conserve kinetic energy, they do obey conservation of momentum. Sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shotgun
A shotgun (also known as a scattergun, or historically as a fowling piece) is a long gun, long-barreled firearm designed to shoot a straight-walled cartridge (firearms), cartridge known as a shotshell, which usually discharges numerous small pellets (petrology), pellet-like spherical sub-projectiles called shot (pellet), shot, or sometimes a single solid projectile called a shotgun slug, slug. Shotguns are most commonly smoothbore firearms, meaning that their gun barrels have no rifling on the inner wall, but rifled barrels for shooting slugs (slug barrels) are also available. Shotguns come in a wide variety of calibers and Gauge (firearms), gauges ranging from 5.5 mm (.22 inch) to up to , though the 12-gauge (18.53 mm or 0.729 in) and 20-gauge (15.63 mm or 0.615 in) bores are by far the most common. Almost all are breechloading, and can be single-barreled, double barreled shotgun, double-barreled, or in the form of a combination gun. Like rifles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BB Gun
A BB gun is a type of air gun designed to shoot metallic spherical projectiles called BBs (not to be confused with similar-looking bearing balls), which are approximately the same size as BB-size lead birdshot used on shotguns ( in diameter). Modern BB guns usually have a smoothbore barrel with a caliber, and use steel balls that measure in diameter and in weight, usually zinc- or copper-plated for corrosion resistance. Some manufacturers still make the slightly larger traditional lead balls that weigh around , which are generally intended for use in rifled barrels (due to lead having better malleability and exerting less wear on riflings). The term "BB gun" is frequently used incorrectly to describe airsoft guns, which shoot plastic pellets (also often referred to as "BBs") that are larger (usually in diameter) but much less dense than metal BBs, and have significantly lower ballistic performance. The term is also sometimes used to describe a pellet gun, which sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannon
A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge, effective range, mobility, rate of fire, angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word ''cannon'' is derived from several languages, in which the original definition can usually be translated as ''tube'', ''cane'', or ''reed''. In the modern era, the term ''cannon'' has fallen into decline, replaced by ''guns'' or ''artillery'', if not a more specific term such as howitzer or mortar, except for high-caliber automatic weapons firing bigger rounds than machine guns, called autocannons. The earliest known depict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muzzleloader
A muzzleloader is any firearm into which the projectile and the propellant charge is loaded from the muzzle of the gun (i.e., from the forward, open end of the gun's barrel). This is distinct from the modern (higher tech and harder to make) designs of breech-loading firearms. The term "muzzleloader" applies to both rifled and smoothbore type muzzleloaders, and may also refer to the marksman who specializes in the shooting of such firearms. The firing methods, paraphernalia and mechanism further divide both categories as do caliber (from cannons to small-caliber palm guns). Modern muzzleloading firearms range from reproductions of sidelock, flintlock and percussion long guns, to in-line rifles that use modern inventions such as a closed breech, sealed primer and fast rifling to allow for considerable accuracy at long ranges. Modern mortars use a shell with the propelling charge and primer attached at the base. Unlike older muzzleloading mortars, which were loaded the same way as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ricochet Firing
Ricochet firing is the firing of artillery at a low angle and non-maximal power so as to cause the shells to skip across the ground. Background In traditional artillery tactics, either a cannon, a howitzer or occasionally a mortar would fire a shot that would just clear the outer parapet of a fortification, and then would bounce or ricochet inside the fortification's bounds. One of the primary purposes of ricochet fire was to dismount artillery and guns positioned on an enemy's fortifications. Additionally, ricochet fire could also be used to cause chaos behind an enemy army's fortifications, as the ricocheting cannonball would devastate logistical structures not fortified to withstand cannon fire. The first European use of ricochet fire (''tir à ricochet'') has been accredited to the Marquis de Vauban A marquess (; french: marquis ), es, marqués, pt, marquês. is a nobleman of high hereditary rank in various European peerages and in those of some of their former col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannonball
A round shot (also called solid shot or simply ball) is a solid spherical projectile without explosive charge, launched from a gun. Its diameter is slightly less than the bore of the barrel from which it is shot. A round shot fired from a large-caliber gun is also called a cannonball. The cast iron cannonball was introduced by a French artillery engineer Samuel J. Besh after 1450; it had the capacity to reduce traditional English castle wall fortifications to rubble. French armories would cast a tubular cannon body in a single piece, and cannonballs took the shape of a sphere initially made from stone material. Advances in gunpowder manufacturing soon led the replacement of stone cannonballs with cast iron ones. Round shot was made in early times from dressed stone, referred to as gunstone (Middle English: ''gunneston''), but by the 17th century, from iron. It was used as the most accurate projectile that could be fired by a smoothbore cannon, used to batter the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Department Of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United States. The DOE oversees the U.S. nuclear weapons program, nuclear reactor production for the United States Navy, energy-related research, and domestic energy production and energy conservation. The DOE was created in 1977 in the aftermath of the 1973 oil crisis. It sponsors more physical science research than any other U.S. federal agency, the majority of which is conducted through its system of National Laboratories. The DOE also directs research in genomics, with the Human Genome Project originating from a DOE initiative. The department is headed by the Secretary of Energy, who reports directly to the president of the United States and is a member of the Cabinet. The current Secretary of Energy is Jennifer Granholm, who has served ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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