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Sports Equipment
Sports equipment, also called sporting goods, are the tools, materials, apparel, and gear, which varies in shapes, size, and usage in a particular sport. It includes balls, nets, rackets, protective gears like helmets, goggles, etc. Since the performer must use a sport equipment, it can also be serve for protection. History and development of sports Historically, many sports players have developed their own sporting equipment over time. For instance, the use of a football dates back to ancient China, between the Warring States period (476–221 BC) and the Han Dynasty (220 AD). As football remains the most popular sport in the 21st century, the material of the ball has completely changed over the centuries; from being made out of animal skin, to being lined with multiple layers of polyester or cotton. As the sporting equipment industry improves, so do the athletes' performance. This is due to the fact that the equipment is more efficient, lighter and stronger, thus forming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Football
American football, referred to simply as football in the United States and Canada and also known as gridiron football, is a team sport played by two teams of eleven players on a rectangular American football field, field with goalposts at each end. The offense (sports), offense, the team with possession of the oval-shaped Ball (gridiron football), football, attempts to advance down the field by Rush (gridiron football), running with the ball or Forward pass#Gridiron football, throwing it, while the Defense (sports), defense, the team without possession of the ball, aims to stop the offense's advance and to take control of the ball for themselves. The offense must advance the ball at least ten yard, yards in four Down (gridiron football), downs or plays; if they fail, they turnover on downs, turn over the football to the defense, but if they succeed, they are given a new set of four downs to continue the Glossary of American football#drive, drive. Points are scored primarily b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball
A ball is a round object (usually spherical, but sometimes ovoid) with several uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for simpler activities, such as catch or juggling. Balls made from hard-wearing materials are used in engineering applications to provide very low friction bearings, known as ball bearings. Black-powder weapons use stone and metal balls as projectiles. Although many types of balls are today made from rubber, this form was unknown outside the Americas until after the voyages of Columbus. The Spanish were the first Europeans to see the bouncing rubber balls (although solid and not inflated) which were employed most notably in the Mesoamerican ballgame. Balls used in various sports in other parts of the world prior to Columbus were made from other materials such as animal bladders or skins, stuffed with various materials. As balls are one of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball (gridiron Football)
In Northern America, a football (also called a pigskin) is a ball, roughly in the form of a lemon, used in the context of playing gridiron football. Footballs are often made of cowhide leather, as such a material is required in professional and collegiate football, although footballs used in recreation and organized youth leagues may be made of rubber, plastic or composite leather (high school football rule books still allow inexpensive all-rubber footballs, though they are less common than leather). History Early balls In the 1860s, manufactured inflatable balls were introduced through the innovations of English shoemaker Richard Lindon. These were much more regular in shape than the handmade balls of earlier times, making kicking and carrying easier. These early footballs were plum-shaped. Some teams used to have white footballs for purposes of night practice. The football changed in 1934, with a rule change that tapered the ball at the ends more and reduced the size ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball (association Football)
A football or soccer ball is the ball used in the sport of association football. The ball's spherical shape, as well as its size, mass, and material composition, are specified by Law 2 of the Laws of the Game (association football), Laws of the Game maintained by the International Football Association Board. Additional, more stringent standards are specified by FIFA and other big governing bodies for the balls used in the competitions they sanction. Early footballs began as animal bladders or stomachs that would easily fall apart if kicked too much. Improvements became possible in the 19th century with the introduction of rubber and discoveries of vulcanization by Charles Goodyear. The modern 32-panel ball design was developed in 1962 by Eigil Nielsen (footballer, born 1918), Eigil Nielsen, and technological research continues to develop footballs with improved performance. The 32-panel ball design was soon joined by 24-panel balls as well as 42-panel balls, both of which improv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennis Ball
A tennis ball is a small, hollow ball used in games of tennis and real tennis. Tennis balls are fluorescent yellow in Professional sports, professional competitions, but in Amateur sports, recreational play other colors are also used. Tennis balls are covered in a fibrous felt, which modifies their aerodynamic properties, and each has a white curvilinear oval covering it. Specifications Modern tennis balls must conform to certain size, weight, deformation, and bounce criteria to be approved for regulation play. The International Tennis Federation (ITF) defines the official diameter as . Balls must have masses in the range . A tennis ball generally has more of a nitrogen and oxygen mixture than the sea level ambient air pressure. Yellow and white are the only colors approved by the ITF. Most balls produced are a fluorescent color known as "optic yellow", first introduced in 1972 following research demonstrating they were more visible on television. What color to call the ball ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrosse Ball
A lacrosse ball is the solid rubber ball that is used, with a lacrosse stick, to play the sport of lacrosse. It is typically white for men's lacrosse (however the PLL uses optic yellow balls for better TV visibility), or yellow for women's lacrosse; but the balls are produced in a wide variety of colours. The current World Lacrosse, NCAA, and NFHS approved specifications are: ; Color: Can be white, yellow or orange. ; Diameter: Between 2.47 and 2.55 inches (6.27 and 6.47cm). ; Weight: Between 5 and ounces (141.75 and 155.92 grams) ; Material: Solid rubber ; Bounce: The ball, when dropped from a height of 72 inches (1.83 meters) must bounce between 43 and 51 inches (1.09 and 1.30 meters). Beginning with the 2014 season, all three governing bodies for lacrosse in the United States ( US Lacrosse, NFHS, NCAA) have mandated that only balls meeting the NOCSAE ball standard may be used for competition. Balls must be emblazoned with the words "Meets NOCSAE Standard" in order to be d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golf Ball
A golf ball is a ball designed to be used in golf. Under the rules of golf, a golf ball has a mass no more than , has a diameter not less than , and performs within specified velocity, distance, and symmetry limits. Like golf clubs, golf balls are subject to testing and approval by The R&A (formerly part of the Royal and Ancient Golf Club of St Andrews) and the United States Golf Association, and those that do not conform with regulations may not be used in competitions ''(Rule 5–1)''. History Early balls It is commonly believed that hard wooden, round balls, made from hardwoods such as beech and box, were used for golf from the 14th through the 17th centuries. Though wooden balls were no doubt used for other similar contemporary stick and ball games, there is no definite evidence that they were actually used in golf in Scotland. It is equally likely, if not more so, that leather balls filled with cows' hair were used, imported from the Netherlands from at least 1486 onwar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cricket Ball
A cricket ball is a hard, solid ball used to play cricket. A cricket ball consists of a cork (material), cork core wound with String (structure), string then a leather cover stitched on, and manufacture is regulated by cricket law at first-class cricket, first-class level. The trajectory of a cricket ball when bowled, through movement in the air, and off the ground, is influenced by the action of the bowler and the condition of the ball and the pitch, while working on the cricket ball to obtain optimal condition is a key role of the fielding side. The principal method through which the batter (cricket), batter scores run (cricket), runs is by hitting the ball, with the bat, into a position where it would be safe to take a run, or by directing the ball through or over the boundary (cricket), boundary. Cricket balls are harder and heavier than Baseball (ball), baseballs. In Test cricket, professional domestic games that spread over a multitude of days, and almost the entirety of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaelic Ball
A Gaelic ball () is the spherical leather football (ball), football used in the sports of Gaelic football and ladies' Gaelic football and international rules football, international rules football. The pattern of panels consists of six groups perpendicular to each other, each group being composed of two trapezoidal panels and one rectangular panel; 18 panels in all. Rules Gaelic football The football is required to weigh 480–500 grams (1.05–1.1 pounds) and have a circumference of 68–70 cm (2 ft ~3 in); therefore, a diameter of about . Smaller balls can be used in under-15 or younger grades. In addition, balls are approved by The Central Competitions Controls Committee "on the basis of compliance with standards and tests set out by The Central Competitions Controls Committee] Footballs shall fully comply with the Playing Gear and Equipment regulations as ratified from time to time by Central Council." Footballs are pumped to 9.75–10 Pounds per square inch, psi (6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basketball (ball)
A basketball is a Sphere, spherical ball used in basketball games. Basketballs usually range in size from very small promotional items that are only a few inches (some centimeters) in diameter to extra large balls nearly in diameter used in training exercises. For example, a youth basketball could be in circumference, while a National Collegiate Athletic Association (NCAA) men's ball would be a maximum of and an NCAA women's ball would be a maximum of . The standard for a basketball in the National Basketball Association (NBA) is in circumference and for the Women's National Basketball Association (WNBA), a maximum circumference of . High school and junior leagues normally use NCAA, NBA or WNBA sized balls. Aside from the court and the baskets, the basketball is the only piece of equipment necessary to play the game of basketball. During the game, the ball must be bounced continuously (Basketball#Dribbling, dribbling), thrown through the air to other players (Basketball#Passi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baseball (ball)
A baseball is the ball used in the sport of baseball. It consists of a rubber or cork center wrapped in yarn and covered with white natural horsehide or cowhide, or a synthetic composite leather. A regulation baseball is in circumference i.e. in diameter, with a weight of . The leather cover is commonly formed from two saddle-shaped pieces stitched together, typically with red-dyed thread. There are 108 stitches on a regulation baseball. That stitching plays a significant role in the trajectory of a thrown baseball due to the drag caused by the interaction between the stitching and the air. Controlling the orientation of the stitches and the speed of the ball's rotation allows a pitcher to affect the behavior of the pitched ball in specific ways. Commonly employed pitches include the curveball, the slider, the two-seam fastball, the four-seam fastball, the sinker, the cutter and the changeup. History In the early, mid-1800s days of baseball, there was a great variety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellipsoid
An ellipsoid is a surface that can be obtained from a sphere by deforming it by means of directional Scaling (geometry), scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a Surface (mathematics), surface that may be defined as the zero set of a polynomial of degree two in three variables. Among quadric surfaces, an ellipsoid is characterized by either of the two following properties. Every planar Cross section (geometry), cross section is either an ellipse, or is empty, or is reduced to a single point (this explains the name, meaning "ellipse-like"). It is Bounded set, bounded, which means that it may be enclosed in a sufficiently large sphere. An ellipsoid has three pairwise perpendicular Rotational symmetry, axes of symmetry which intersect at a Central symmetry, center of symmetry, called the center of the ellipsoid. The line segments that are delimited on the axes of symmetry by the ellipsoid are called the ''principal ax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
