Work (electrical)

Electrical work is the work done on a charged particle by an electric field. The equation for 'electrical' work is equivalent to that of 'mechanical' work:

where

The electrical work per unit of charge, when moving a negligible test charge between two points, is defined as the voltage between those points.

Overview

Qualitative overview

Particles that are free to move, if positively charged, normally tend towards regions of lower voltage (net negative charge), while if negatively charged they tend to shift towards regions of higher voltage (net positive charge).

However, any movement of a positive charge into a region of higher voltage requires external work to be done against the field of the electric force, work equal to that electric field would do in moving that positive charge the same distance in the opposite direction. Similarly, it requires positive external work to transfer a negatively charged particle from a region of higher voltage to a region of lower voltage.

The electric force is a conservative force: work done by a static electric field is independent of the path taken by the charge. There is no change in the voltage (electric potential) around any closed path; when returning to the starting point in a closed path, the net of the external work done is zero. The same holds for electric fields.

Work of art

A work of art, artwork, art piece, piece of art or art object is an aesthetic physical item or artistic creation. Apart from "work of art", which may be used of any work regarded as art in its widest sense, including works from literature and music, these terms apply principally to tangible, portable forms of visual art:

Used more broadly, the term is less commonly applied to:

Work (Rihanna song)

"Work" is a song recorded by Barbadian singer Rihanna for her eighth studio album, Anti (2016). The song features a verse by Canadian rapper Drake. The artists co-wrote the single with PartyNextDoor, Allen Ritter, Rupert Thomas, R. Stephenson, Monte Moir, and Boi-1da; the latter is also the producer.

Upon its release, "Work" received mixed reviews from music critics. The song debuted at number nine and has so far peaked at number seven on the Billboard Hot 100, becoming Rihanna's 27th and Drake's 15th top ten entry on the chart. It has also peaked within the top ten of the charts in Australia, Canada, France, Hungary, Spain, and the United Kingdom.

Writing and development

"Work" was written by the artists, PartyNextDoor, Allen Ritter, Rupert "Sevn" Thomas, Monte Moir, R. Stephenson, and Boi-1da; the latter is also the producer. In the summer of 2015, Thomas, Ritter, Boi-1da and Martin Mason among others, stayed at Drake house in Los Angeles for a mid-week period. Thomas described the time spent at the home as a "beat factory, everyone was sitting there working and collaborating with each other." Thomas created a beat which was dancehall-influenced; he later played it for Boi-1da to which he positively responded, "We’re both Jamaican-Canadian. It was just something in our DNA, so it woke him up, and we started remembering all these old dancehall songs from the '90s." Boi-1da came with up idea for sampling an "old school dancehall rhythm" and after that the chords were made with Ritter and past it, "everything went organically".

Football (video game)

Football (released as NFL Football) is a multiplayer sports video game produced by Mattel and released for its Intellivision video game system in 1979. The players each control a football team competing in a standard four-quarter game. Like Mattel's other sports video games, NFL Football did not use any official National Football League team names or player names, even though Mattel obtained a license from the NFL and used the league's logo in its box art.

Gameplay

The player controls a five-man football team, actively controlling one team member at a time, with the computer controlling the rest. As in traditional American football, the player's team must score more points than the opponent's team within the time limit of the game. The game consists of four quarters, each a simulated 15 minutes in length, and takes place on a horizontally scrolling 100-yard simulated football field.

Player 1 always starts the game on offense and receives the opening kick-off from Player 2; at the start of the second half, Player 2 will receive the kick-off from Player 1. NFL Football is played in the same basic manner as a regulation game of football, with the offense being given four downs to advance the ball a minimum of ten yards before losing possession of the football to the opposing team. At the start of each down, the players use their controller's keypad to input a formation and a play for that down; descriptions and diagrams of the plays were printed in the game's instruction manual and not visible on-screen. When both players have entered their formations, play resumes.

Ball (association football)

A football, soccer ball, or association football ball is the ball used in the sport of association football. The name of the ball varies according to whether the sport is called "football", "soccer", or "association football". The ball's spherical shape, as well as its size, weight, 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 subordinate 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, and technological research continues today to develop footballs with improved performance.

History

In 1863, the first specifications for footballs were laid down by the Football Association. Previous to this, footballs were made out of inflated leather, with later leather coverings to help footballs maintain their shapes. In 1872 the specifications were revised, and these rules have been left essentially unchanged as defined by the International Football Association Board. Differences in footballs created since this rule came into effect have been to do with the material used in their creation.

American football

American football (referred to as football in the United States and Canada, also known as gridiron elsewhere) is a sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team with control of the oval-shaped football, attempts to advance down the field by running with or passing the ball, while the team without control of the ball, the defense, aims to stop their advance and take control of the ball for themselves. The offense must advance at least ten yards in four downs, or plays, or else they turn over the football to the opposing team; if they succeed, they are given a new set of four downs. Points are primarily scored by advancing the ball into the opposing team's end zone for a touchdown or kicking the ball through the opponent's goalposts for a field goal. The team with the most points at the end of a game wins.

American football evolved in the United States, originating from the sports of association football and rugby football. The first game of American football was played on November 6, 1869, between two college teams, Rutgers and Princeton, under rules based on the association football rules of the time. During the latter half of the 1870s, colleges playing association football switched to the Rugby Union code, which allowed carrying the ball. A set of rule changes drawn up from 1880 onward by Walter Camp, the "Father of American Football," established the snap, eleven-player teams, and the concept of downs; later rule changes legalized the forward pass, created the neutral zone, and specified the size and shape of the football.