A back lever is a static hold performed on the rings or the pull-up bar. A back lever is rated as an 'A' value skill on the Code of Points, a scale from A to F, with F being the most difficult.
A back lever is performed by lowering from an inverted hang until the gymnast's body is parallel to the ground and facing towards the floor.
Performing a back lever requires a high degree of strength in the back and biceps, a lot of core tension must be generated to stay horizontal.
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Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the law of the lever. Machine components designed to manage forces and movement in this way are called mechanisms. An ideal mechanism transmits power without adding to or subtracting from it. This means the ideal machine does not include a power source, is frictionless, and is constructed from rigid bodies that do not deflect or wear. The performance of a real system relative to this ideal is expressed in terms of efficiency factors that take into account departures from the ideal.
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage to multiply force. Usually the term refers to the six classical simple machines that were defined by Renaissance scientists:
In physics and mechanics, torque is the rotational analogue of linear force. It is also referred to as the moment of force. It describes the rate of change of angular momentum that would be imparted to an isolated body.
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or fulcrum. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is divided into three types. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage, which is mechanical advantage gained in the system, equal to the ratio of the output force to the input force. As such, the lever is a mechanical advantage device, trading off force against movement.
In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. It outputs a bit opposite of the bit that is put into it. The bits are typically implemented as two differing voltage levels.
An operant conditioning chamber is a laboratory apparatus used to study animal behavior. The operant conditioning chamber was created by B. F. Skinner while he was a graduate student at Harvard University. The chamber can be used to study both operant conditioning and classical conditioning.
Calisthenics or callisthenics (/ˌkælɪsˈθɛnɪks/) is a form of strength training that utilizes an individual's body weight as resistance to perform multi-joint, compound movements with little or no equipment.
A torsion spring is a spring that works by twisting its end along its axis; that is, a flexible elastic object that stores mechanical energy when it is twisted. When it is twisted, it exerts a torque in the opposite direction, proportional to the amount (angle) it is twisted. There are various types:
A pocket watch is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist.
Kick start is a method of starting an internal combustion engine by pushing a ratcheting lever with one's foot. Kick start mechanisms were almost universally a part of motorcycle engines before the mid-1970s, and were phased out of production over the next twenty years or so as electric starters became standard equipment. There are still some motorcycles produced that have both kick and electric starters.
Johnny Lever is an Indian actor and popular comedian who is known for his works in Hindi cinema. He is one of the first stand-up comedians in India. He is the recipient of numerous accolades, including thirteen Filmfare Awards nominations in Filmfare Award for Best Performance in a Comic Role, and has won the award twice, for his work in Deewana Mastana (1997) and Dulhe Raja (1998). He began his career in 1984, and has acted in more than three hundred Hindi films.
Shaping is a conditioning paradigm used primarily in the experimental analysis of behavior. The method used is differential reinforcement of successive approximations. It was introduced by B. F. Skinner with pigeons and extended to dogs, dolphins, humans and other species. In shaping, the form of an existing response is gradually changed across successive trials towards a desired target behavior by reinforcing exact segments of behavior. Skinner's explanation of shaping was this:
We first give the bird food when it turns slightly in the direction of the spot from any part of the cage. This increases the frequency of such behavior. We then withhold reinforcement until a slight movement is made toward the spot. This again alters the general distribution of behavior without producing a new unit. We continue by reinforcing positions successively closer to the spot, then by reinforcing only when the head is moved slightly forward, and finally only when the beak actually makes contact with the spot. ... The original probability of the response in its final form is very low; in some cases it may even be zero. In this way we can build complicated operants which would never appear in the repertoire of the organism otherwise. By reinforcing a series of successive approximations, we bring a rare response to a very high probability in a short time. ... The total act of turning toward the spot from any point in the box, walking toward it, raising the head, and striking the spot may seem to be a functionally coherent unit of behavior; but it is constructed by a continual process of differential reinforcement from undifferentiated behavior, just as the sculptor shapes his figure from a lump of clay.
The Canon FT QL is a 35mm single-lens reflex camera introduced by Canon Inc. in March 1966. It has a Canon FL lens mount compatible with the large range of FL series lenses. The FT can also operate the later Canon FD series lenses in stop-down mode, but the earlier R series has a different lens aperture mechanism and cannot be used, although the bayonet fitting is similar. The standard kit lenses were Canon's 50mm f/1.8 ; 50mm f/1.4 and 58mm f/1.2, the body-only option was offered later.
A flashkick is a type of back flip that is performed in the martial art of tricking, usually performed with one leg extended and the other tucked. As with many other types of back flips, a flashkick may be started from a stationary standing position or immediately following another similar move, such as a roundoff.
The Bell Rocket Belt is a low-power rocket propulsion device that allows an individual to safely travel or leap over small distances. It is a type of rocket pack.
A freeze is a b-boying technique that involves halting all body motion, often in an interesting or balance-intensive position. It is implied that the position is hit and held from motion as if freezing in motion, or into ice. Freezes often incorporate various twists and distortions of the body into stylish and often difficult positions.
A breaker bar is a long non-ratcheting bar that is used with socket wrench-style sockets. They are used to break loose very tight fasteners because their additional length allows the same amount of force to generate significantly more torque than a standard length socket wrench. Their use prevents damage to the ratcheting mechanism of a socket wrench. Often, after the first half turn, the fastener is loose enough to be turned with a socket wrench.
The front lever is a gymnastic and calisthenic move - a static hold normally performed on the still rings or the pull-up bar. A front lever is performed by lowering from an inverted hang until the body is completely horizontal and straight with the front of the body facing upwards. An accomplished gymnast may also pull directly into the horizontal position from a dead hang. Front levers require a high degree of back and core strength.
A marine steam engine is a steam engine that is used to power a ship or boat. This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the steamboat in the early 19th century to their last years of large-scale manufacture during World War II. Reciprocating steam engines were progressively replaced in marine applications during the 20th century by steam turbines and marine diesel engines.
Dr Ashok Shekar Ganguly noted industry expert and former chairman of Hindustan Lever, was a nominated member of the Rajya Sabha. His term ended on 17 November 2015.