Rules of The Court

It may seem like there is no more to basketball than putting a ball in a basket. However, there are certain rules that teams must play by in order to create a fair game. Referees police the action of the game and blow a whistle to indicate violations. Referees also use hand signals to indicate the type of violation that has occurred.

College vs. Pro The rules of play for the NCAA are not exactly the same as for the NBA. For instance, a college game is divided into two 20-minute segments, while a pro game is broken into four 12-minute segments. And while a college team gets 35 seconds to shoot the ball before turning it over to the opposing team, a pro shot clock runs out in just 24 seconds! For more information on the distinctions between organizations, see USA Basketball.com.

An official game is played for a set amount of time, and the team that scores the most points at the end of that time is declared the winner. If the two teams are tied at the end of the game, the teams play overtime periods until a winner is determined. Each overtime period last five minutes, and when one team is ahead at the end of an overtime period, the game is over.

Within the game, there are certain rules that players have to follow. Here are some of basketball’s most commonly noted ones:

• If an offensive team allows the ball to go behind the midcourt line and touches it before the opposing team touches it, it is called for a backcourt violation and the opposing team is awarded the ball.
• A player must bounce the ball on the court, also called dribbling, in order to move around the court. A player can move only two steps after he stops dribbling. If a player dribbles, stops, and then dribbles again, the referee calls a double-dribble violation, and the opposing team gains possession of the ball.

Court and Equipment of Basketball

Basketball can be played anywhere as long as there is a hoop mounted to a pole or wall and a ball to shoot through it. The basic idea could hardly be simpler. The two teams want to do two things:

• Get the ball through the opposing team’s basket as much as possible (offense)
• Stop the opposing team from doing the same thing (defense)

As soon as one team has the ball, that team is the offense and the other team is the defense. The offense tries to position players to take a shot (throw the ball through the hoop). The defense players position themselves to block these shots. Offense players move around the basket and cut past defense players (abruptly changing direction to get past the defense) until they can set up a reasonably clear shot.

The way all this plays out largely depends on the court. Dimensions of the court and other equipment vary depending on the level of play. For our purposes, we will look at the National Basketball Association’s (NBA) regulation equipment.

In its original form, when peach baskets were used, contestants climbed up a ladder to retrieve the ball after making a basket. Baskets are still used in basketball, but have evolved to eliminate the manual retrieval of the ball. Today’s basket is an 18-inch-diameter (46 cm) metal rim, with a 15- or 18-inch-long (38 or 46 cm), open-ended nylon net extending below it.

The rim is actually about twice the diameter of a regulation basketball. In the NBA, the official ball is made of leather and has a circumference of 30 inches (76 cm) and a diameter of 9 inches (23 cm). Prior to play, the ball must be inflated to 7.5 to 8.5 pounds of pressure (0.51 to 0.57 atm).

An official basketball court, where competitive games are played, is a rectangle divided into two halves by the midcourt line. On each end of the court, baskets are mounted to a backboard and raised to a height of 10 feet (3 m). The backboard is a rectangle that is 6 feet (1.8 m) wide and 3.5 feet (1 m) tall. Players often shoot the ball at an angle so that it ricochets off the backboard and into the basket.

How Basketball Works

Basketball can be played by as few as two players. However, organized basketball games include two teams comprised of five players per team. Each team can have more than five players, but only five players per team are allowed on the court at one time.

The team’s head coach determines when players go in and come out of the game. Reserve players enter the game through a process called substitution. Substitutions can only occur when play stops, such as during a timeout or when the referee calls a violation.

Each player on a team is categorized by position. There are five positions on a traditional basketball team:

• Point guard – This player is typically the best dribbler and passer on the team. The point guard is sometimes called the floor general, which indicates the key role that the point guard plays.
• Shooting guard – The shooting guard, also called the two guard, is typically a team’s best outside shooter on the team. This player flanks the point guard and moves around the court to try to create some space to take a shot that is uncontested by the opposition.
• Power forward – The power forward is usually near the basket and moves from one side of the basket to the other to try to get free from the opposition player that is guarding him. Power forwards also are skilled rebounders.
• Small forward – The small forward is typically a better outside shooter than a power forward and is usually smaller than a power forward.
• Center – Traditionally, the center is the tallest player on the team. The center’s role is to establish a position near the basket to allow him/herself an easy jump shot. On defense, the center attempts to block shots and grab rebounds.

Unsur Hara

Beberapa Unsur Hara Yang Dibutuhkan Tanaman
Selama masa pertumbuhan dan perkembangan, tanaman membutuhkan beberapa unsur hara yang meliputi: Karbon (C), Hidrogen (H), Oksigen (O), Nitrogen (N), Fosfor (P), Kalium (K), Kalsium (Ca), Magnesium (Mg), Belerang (S), Besi (Fe), Mangan (Mn), Boron (B), Mo, Tembaga (Cu), Seng (Zn) dan Klor (Cl). Unsur hara tersebut tergolong unsur hara Essensial. Unsur hara essensial ini berdasarkan jumlah kebutuhannya bagi tanaman, dikelompokkan menjadi dua, yaitu: (1) unsur hara yang diperlukan tanaman dalam jumlah besar disebut Unsur Hara Makro, dan (2) unsur hara yang diperlukan tanaman dalam jumlah kecil disebut Unsur Hara Mikro. Unsur hara makro meliputi: N, P, K, Ca, Mg, dan S. Unsur hara mikro meliputi: Fe, Mn, B, Mo, Cu, Zn, dan Cl.

Mekanisme Penyediaan Unsur Hara
Penyediaan unsur hara untuk tanaman terdiri dari tiga kategori, yaitu: (1) tersedia dari udara, (2) tersedia dari air yang diserap akar tanaman, dan (3) tersedia dari tanah. Beberapa unsur hara yang tersedia dalam jumlah cukup dari udara adalah: (a) Karbon (C), dan (b) Oksigen (O), yaitu dalam bentuk karbon dioksida (CO2). Unsur hara yang tersedia dari air (H2O) yang diserap adalah: hidrogen (H), karena oksigen dari molekul air mengalami proses oksidasi dan dibebaskan ke udara oleh tanaman dalam bentuk molekul oksigen (O2). Sedangkan untuk unsur hara essensial lain yang diperlukan tanaman tersedia dari dalam tanah.

Koloid Tanah

Koloid tanah adalah bahan organik dan bahan mineral tanah yang sangat halus sehingga mempunyai luas permukaan yang sangat tinggi persatuan berat. Koloid tanah terdiri dari liat (koloid anorganik) dan humus (kolod organik). Koloid berukuran kurang dari 1 µ, sehingga tidak semua fraksi liat (kurang dari 2 µ) termasuk koloid.

Koloid anorganik terdiri dari mineral liat Al-silikat, oksida-oksida Fe dan Al, mineral-mineral primer.

Mineral liat Al-silikat mempunyai bentuk kristal yang baik misalnya kaolinit, haolisit, montmorilonit, ilit. Kaolinit dan haolisit banyak ditemukan pada tanah-tanah merah (coklat) yaitu tanah-tanah yang umumnya berdrainase baik, sedangkan montmorilonit ditemukan pada tanah-tanah yang mudang mengembang dan mengerut serta pecah-pecah pada musim kering misalnya tanah vertisol. Ilit ditemukan pada tanah-tanah berasal dari bahan induk yang banyak mengandung mika dan belum mengalami pelapukan lanjut. Adanya muatan negatif pada mineral liat disebabkan oleh beberapa hal yaitu : (1) Kelebihan muatan negatif pada ujung-ujung patahan kristal baik pada Si-tetrahedron maupun Al-oktahedron, (2) Disosiasi H⁺ dari gugus OH yang terdapat pada tepi atau ujung kristal, (3) Substitusi isomorfik.