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Tread Water
Treading water or water treading is what a swimmer can do while in a vertical position to keep their head above the surface of the water, while not providing sufficient directional thrust to overcome inertia and propel the swimmer in any specific direction. As it expends less energy than traditional strokes, it is often used by swimmers to rest in between periods of exertion without having to leave the water. In figurative language, the expression "treading water" has become a metaphor for an effort expected to create motion, but which actually results in merely staying in one, possibly barely sustainable, place. Methods Any sort of movement that allows the swimmer to do this can be classified as treading water, but it is more efficient to move the arms and legs in a specific fashion. Non-swimmers often splash and kick in an effort to stay above the surface but their lack of technique along with shortness of breath and the panic factor make for a very ineffective method of tread ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Swimming
Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that results in directional motion. Humans can hold their breath underwater and undertake rudimentary locomotive swimming within weeks of birth, as a survival response. Swimming is consistently among the top public recreational activities, and in some countries, swimming lessons are a compulsory part of the educational curriculum. As a formalized sport, swimming is featured in a range of local, national, and international competitions, including every modern Summer Olympics. Swimming involves repeated motions known as strokes in order to propel the body forward. While the front crawl, also known as freestyle, is widely regarded as the fastest out of four primary strokes, other strokes are practiced for special purposes, such as for training. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust
Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that system. The force applied on a surface in a direction perpendicular or normal to the surface is also called thrust. Force, and thus thrust, is measured using the International System of Units (SI) in newtons (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second. In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as static thrust. Examples A fixed-wing aircraft propulsion system generates forward thrust when air is pushed in the direction opposite to flight. This can be done by different means such as the spinning blades of a propeller, the propelling jet of a jet engine, or by ejecting hot gases from a rocket ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertia
Inertia is the idea that an object will continue its current motion until some force causes its speed or direction to change. The term is properly understood as shorthand for "the principle of inertia" as described by Newton in his first law of motion. After some other definitions, Newton states in his first law of motion: The word "perseveres" is a direct translation from Newton's Latin. Other, less forceful terms such as "to continue" or "to remain" are commonly found in modern textbooks. The modern use follows from some changes in Newton's original mechanics (as stated in the ''Principia'') made by Euler, d'Alembert, and other Cartesians. The term inertia comes from the Latin word ''iners'', meaning idle, sluggish. The term inertia may also refer to the resistance of any physical object to a change in its velocity. This includes changes to the object's speed or direction of motion. An aspect of this property is the tendency of objects to keep moving in a straight li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figurative Language
Literal and figurative language is a distinction within some fields of language analysis, in particular stylistics, rhetoric, and semantics. *Literal language uses words exactly according to their conventionally accepted meaning (linguistics), meanings or denotation. *Figurative (or non-literal) language uses words in a way that deviates from their conventionally accepted definitions in order to convey a more complicated meaning or heightened effect. Figurative language is often created by presenting words in such a way that they are equated, compared, or associated with normally unrelated meanings. Literal usage confers meaning to words, in the sense of the meaning they have by themselves, outside any figure of speech. It maintains a consistent meaning regardless of the context (language use), context, with ''the intended meaning corresponding exactly to the meaning'' of the individual words. On the contrary, figurative use of language is the use of words or phrases that ''implie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaphor
A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two different ideas. Metaphors are often compared with other types of figurative language, such as antithesis, hyperbole, metonymy, and simile. One of the most commonly cited examples of a metaphor in English literature comes from the "All the world's a stage" monologue from '' As You Like It'': All the world's a stage, And all the men and women merely players; They have their exits and their entrances And one man in his time plays many parts, His Acts being seven ages. At first, the infant... :—William Shakespeare, '' As You Like It'', 2/7 This quotation expresses a metaphor because the world is not literally a stage, and most humans are not literally actors and actresses playing roles. By asserting that the world is a stage, Shakespeare uses points of comparison between the world an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sculling
Sculling is the use of oars to propel a boat by moving them through the water on both sides of the craft, or moving one oar over the stern. A long, narrow boat with sliding seats, rigged with two oars per rower may be referred to as a scull, its oars may be referred to as sculls and a person rowing it referred to as sculler. Sculling is distinguished from sweep rowing, whereby each boat crew member employs an oar, complemented by another crew member on the opposite side with an oar, usually with each pulling it with two hands and from stern sculling, which uses an oar to propel a vessel with side-to-side movements from the stern. Overview Sculling is a form of rowing in which a boat is propelled by one or more rowers, each of whom operates two oars, one held in the fingers and upper palm of each hand. This contrasts with the other common method of rowing, sweep rowing, in which each rower may use both hands to operate a single oar on either the port or starboard side of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flutter Kick
The flutter kick is a kicking movement used in both swimming and calisthenics. Swimming In swimming strokes such as the front crawl or backstroke, the primary purpose of the flutter kick is not propulsion but keeping the legs up and in the shadow for the upper body and assisting body rotation for arm strokes. The legs are extended straight backwards in line with the body. They are moved up and down, one leg kicking downwards (relative to the front of the swimmer's body) as the other leg moves up. The knees are slightly bent to facilitate the kicking action, but not too much in order to minimise drag created by the thighs as they move out of the shadow of the swimmer's body. Similarly, toes are pointed to minimize drag. The downward moving leg provides the thrust. An integral part of the kick is the flexing of the ankles; it is the flexing of the ankle that allows the foot to provide thrust. The knees are not kept rigid when kicking but are allowed to flex slightly to allow the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle
A bicycle, also called a pedal cycle, bike or cycle, is a human-powered or motor-powered assisted, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A is called a cyclist, or bicyclist. Bicycles were introduced in the 19th century in Europe. By the early 21st century, more than 1 billion were in existence. These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced. They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys, general fitness, military and police applications, courier services, bicycle racing, and bicycle stunts. The basic shape and configuration of a typical upright or "safety bicycle", has changed little since the first chain-driven model was developed around 1885. However, many details have been improved, especially since the advent of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lifeguard
A lifeguard is a rescuer who supervises the safety and rescue of swimmers, surfers, and other water sports participants such as in a swimming pool, water park, beach, spa, river and lake. Lifeguards are trained in swimming and CPR/ AED first aid, certified in water rescue using a variety of aids and equipment depending on requirements of their particular venue. In some areas, lifeguards are part of the emergency services system to incidents and in some communities, lifeguards may function as the primary EMS provider. Responsibilities A lifeguard is responsible for the safety of people in an area of water, and usually a defined area immediately surrounding or adjacent to it, such as a beach next to an ocean or lake. The priority is to ensure no harm comes to users of the area for which they are responsible. Lifeguards often take on this responsibility upon employment, although they can also be volunteers. The conditions resulting in drowning are summarized by the 'drowning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Aid
First aid is the first and immediate assistance given to any person with either a minor or serious illness or injury, with care provided to preserve life, prevent the condition from worsening, or to promote recovery. It includes initial intervention in a serious condition prior to professional medical help being available, such as performing cardiopulmonary resuscitation (CPR) while waiting for an ambulance, as well as the complete treatment of minor conditions, such as applying a plaster to a cut. First aid is generally performed by someone with basic medical training. Mental health first aid is an extension of the concept of first aid to cover mental health, while psychological first aid is used as early treatment of people who are at risk for developing PTSD. Conflict First Aid, focused on preservation and recovery of an individual's social or relationship well-being, is being piloted in Canada. There are many situations that may require first aid, and many countries hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Polo
Water polo is a competitive team sport played in water between two teams of seven players each. The game consists of four quarters in which the teams attempt to score goals by throwing the ball into the opposing team's goal. The team with the most goals at the end of the game wins the match. Each team is made up of six field players and one goalkeeper. Excluding the goalkeeper, players participate in both offensive and defensive roles. It is typically played in an all-deep pool where players cannot touch the bottom. A game consists mainly of the players swimming to move about the pool, treading water (mainly using the eggbeater kick), passing the ball, and shooting at the goal. Teamwork, tactical thinking and awareness are also highly important aspects. Water polo is a highly physical and demanding sport and has frequently been cited as one of the most difficult to play. Special equipment for water polo includes a water polo ball, a ball of varying colors which floats on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
