A ball is a round object 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.
In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word collision refers to incidents in which two or more objects collide with great force, the scientific use of the term implies nothing about the magnitude of the force.
A hockey puck is either an open or closed disk used in a variety of sports and games. There are designs made for use on an ice surface, such as in ice hockey, and others for the different variants of floor hockey which includes the wheeled skate variant of inline hockey. They are all designed to serve the same function a ball does in ball games.
Silly Putty is a toy containing silicone polymers that have unusual physical properties. It can flow like a liquid, bounce and can be stretched or broken depending on the amount of physical stress to which it is subjected. It contains viscoelastic liquid silicones, a type of non-Newtonian fluid, which makes it act as a viscous liquid over a long period of time but as an elastic solid over a short time period. It was originally created during research into a potential rubber substitute for use by the United States in World War II.
Wham-O Inc. is an American toy company based in Carson, California, United States. It is known for creating and marketing many popular toys for nearly 70 years, including the Hula hoop, Frisbee, Slip 'N Slide, Super Ball, Trac-Ball, Silly String, Hacky sack, Wham-O Bird Ornithopter and Boogie Board, many of which have become genericized trademarks.
A beach ball is an inflatable ball for beach and water games. Their large size and light weight require little effort to propel them.
A Spalding Hi-Bounce Ball, often called a Spaldeen or a Pensie Pinkie, is a rubber ball, described as a tennis ball core without the felt. These balls are commonly used in street games developed in the mid-20th century, such as Chinese handball, Australian Handball, stoop ball, hit-the-penny, butts up, handball, punchball, boxball, half-rubber, Wireball and stickball.
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 1.620 oz (45.93 g), has a diameter not less than 1.680 inches (42.67 mm), and performs within specified velocity, distance, and symmetry limits. Like golf clubs, golf balls are subject to testing and approval by The R&A and the United States Golf Association, and those that do not conform with regulations may not be used in competitions (Rule 5–1).
Newton's cradle is a device, usually made of metal, that demonstrates the principles of conservation of momentum and conservation of energy in physics with swinging spheres. When one sphere at the end is lifted and released, it strikes the stationary spheres, compressing them and thereby transmitting a pressure wave through the stationary spheres, which creates a force that pushes the last sphere upward. The last sphere swings back and strikes the stationary spheres, repeating the effect in the opposite direction. The device is named after 17th-century English scientist Sir Isaac Newton and was designed by French scientist Edme Mariotte. It is also known as Newton's pendulum, Newton's balls, Newton's rocker or executive ball clicker.
A Super Ball or Superball is a toy bouncy ball based on a type of synthetic rubber invented in 1964 by chemist Norman Stingley. It is an extremely elastic ball made of Zectron, which contains the synthetic polymer polybutadiene as well as hydrated silica, zinc oxide, stearic acid, and other ingredients. This compound is vulcanized with sulfur at a temperature of 165 °C (329 °F) and formed at a pressure of 3,500 psi (24 MPa). The resulting Super Ball has a very high coefficient of restitution, and if dropped from shoulder level on a hard surface, a Super Ball bounces nearly all the way back; thrown down onto a hard surface by an average adult, it can fly over a three-story building.
A tennis ball is a small, hollow ball used in games of tennis and real tennis. Tennis balls are fluorescent yellow in professional competitions, but in 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.
A bowling ball is a hard spherical ball used to knock down bowling pins in the sport of bowling.
In physics, the coefficient of restitution, can be thought of as a measure of the elasticity of a collision between two bodies. It is a dimensionless parameter defined as the ratio of the relative velocity of separation after a two-body collision to the relative velocity of approach before collision. In most real-word collisions, the value of e lies somewhere between 0 and 1, where 1 represents a perfectly elastic collision and 0 a perfectly inelastic collision. The basic equation, sometimes known as Newton's restitution equation was developed by Sir Isaac Newton in 1687.
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, weight, mass, and material composition, are specified by Law 2 of the 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.
Juggling balls, or simply balls, are a popular prop used by jugglers, either on their own—usually in sets of three or more—or in combination with other props such as clubs or rings. A juggling ball refers to any juggling object that is roughly spherical in nature.
Waboba is an international outdoor toy and sporting goods brand headquartered in Stockholm, Sweden with offices in Atlanta, Georgia and Guangzhou, China. Waboba is most known for its invention of balls that bounce on water, the high bouncing Moon ball, and the Wingman silicone flying disc. The company specializes in beach and backyard toys and games. The slogan used in advertising is Keep Life Fun. The name Waboba is a registered trademark and many of its products are internationally patented.
The Sky Ball is a mid-sized bouncy ball toy sold by Maui Toys. Each ball measures 4 inches (10 cm) in diameter and contains a mix of helium and compressed air.
A Galilean cannon is a device that demonstrates conservation of linear momentum. It comprises a stack of balls, starting with a large, heavy ball at the base of the stack and progresses up to a small, lightweight ball at the top. The basic idea is that this stack of balls can be dropped to the ground and almost all of the kinetic energy in the lower balls will be transferred to the topmost ball - which will rebound to many times the height from which it was dropped. At first sight, the behavior seems highly counter-intuitive, but in fact is precisely what conservation of momentum predicts. The principal difficulty is in keeping the configuration of the balls stable during the initial drop. Early descriptions involve some sort of glue/tape, tube, or net to align the balls.
Waterballs are water toys that are played on the water surface with players interacting with the water toy and the water in any number of play patterns. Generally players throw waterballs at varying speeds across the water and air at varying angles to get the desired skip pattern. Play is generally between players and play patterns can involve a variety of apparatus and equipment, such as special pools with goals and watercourts.
The physics of a bouncing ball concerns the physical behaviour of bouncing balls, particularly its motion before, during, and after impact against the surface of another body. Several aspects of a bouncing ball's behaviour serve as an introduction to mechanics in high school or undergraduate level physics courses. However, the exact modelling of the behaviour is complex and of interest in sports engineering.
