golf(gao er fu )

Golf practice:

Raw materials for golf:

Buttered, green coconut, mint cream. Seasoning: cake germ: white oil = 1:1.

Golf production steps:

1. Use S.P sponge cake embryo to make a square shape, cut into three layers, insert white deoiling in the middle, scrape white deoiling on the top and vertical sides, and sprinkle green coconut silk on the surface and around.

2. Decorate the golfer with mint cream and chocolate.

Golf

synonym

Golf (an outdoor sport) generally refers to golf (a sport)

This entry is compiled and applied by "popular science China" Science Encyclopedia

to examine

.

Golf is a transliteration of golf, which is made up of four acronyms. They are: green, oxygen, light, friendship. It means "green, oxygen, sunshine, friendship". It is a kind of sport that combines enjoying the fun of nature, physical exercise and games. Golf is a kind of ball game in which the ball hits the hole with a stick. Nowadays, modern golf has become the synonym of aristocratic sports, which is the evolution of an ancient Chinese game called chuiwan.

brief introduction

"Golf" originally means "a good life in green space and fresh air". This can be seen from the English word Golf: G - green; O - oxygen; L - light; F - friendship. It is a kind of sport that combines enjoyment of nature, physical exercise and games.

Golf shape

There are many dents on the surface of the golf ball.

The shape of golf ball is one of the results of aerodynamics research. This is related to the turbulent transition and separated flow of the flow around a sphere.

The regular flow corresponding to turbulence is called laminar flow. The laminar boundary layer is prone to flow separation (that is, the streamline leaves the surface of the ball), and a high pressure region is formed in the face of the ball, and a large low pressure region is formed in the back, resulting in a large resistance (differential pressure resistance). Make the golf ball fly a small distance.

When there is a dent on the surface of the sphere, the dent promotes the turbulent transition, and the turbulent boundary layer is not easy to flow separation, so that the low pressure area behind the sphere is small and the drag is reduced. Increase the distance the golf ball flies.

The friction of turbulent flow is larger than that of laminar flow, but it plays a very small role compared with the shape resistance, and the total resistance is still smaller.

Small protrusions on the surface of golf balls can also promote separation, but the interference of protrusions on the flow is difficult to control, resulting in some lateral forces (also known as lift).

There is no lift force in the regular flow around a sphere. Rotation produces lift. The appropriate lift drag ratio will increase the flight distance. Different rotation directions will cause the effect of "banana ball".

In addition, the golf rules stipulate that golf balls shall not be designed, manufactured or intentionally changed to have characteristics different from those of balls with spherical symmetry.

The origin of golf

It is said that Scotland is the birthplace of golf. At that time, shepherds often hit stones with sheep driving sticks. They hit far and accurately in the game. This is the early golf.

In the 19th century, golf was introduced into the United States. In 1922, the first international competition in the world was the "Walker Cup" golf match between the United States and Britain. Golf was introduced into China in the early 20th century. Golf is played on the open grassland with 9 or 18 holes. Players hit the ball into the hole one by one, and those who hit the ball less times win. The competition is generally divided into singles and team.

In 1860, England held the first golf open. In this year, India, Canada, New Zealand, the United States and other countries also held competitions one after another, followed by international, intercontinental and even global competitions. The world cup, England and the US Open are the highest level competitions of golf.

Golf originated in Scotland in the 15th century. At that time, shepherds often used the stick to drive sheep to play a game of hitting stones, to compare who can hit far and accurately. This game later evolved into golf. In the film "Hobbit", Gandalf said that the origin of golf is: "Bilbo Baggins's great great great uncle" roaring cow "tuk fought the orc army in the battle of Greenland, swung the orc King's head down with a club, and the head flew hundreds of meters directly into the rabbit hole. So he won the battle and invented the golf game! " At that time, a lot of audience laughed in the cinema!!

According to the records of marujing, chuiwan players respect each other and consider how to hit the ball from each other's standpoint, which is a very gentlemanly sport. The painting "tuiwan mural" in Yuan Dynasty also proves that "chuiwan" is the present golf.

The painting of "Xuanzong Xingyue" in Ming Dynasty also confirmed this view. The robust Xuanzong is staring forward with a stick, as if thinking about how to swing. The big tree in the middle is like a big window. Up to about 10 meters, Xuanzong is ready to hit the ball over the tree. In one corner of the picture, there is a caddie running with a club. Actually, "Chui Wan" evolved from the Chinese mainland's "step ball". There is no way to know when it started. Marujing is a book that people used to explain the rules of chuiwan in detail at that time.

Chuiwan is the same as golf. For example, "when a man hits a wooden ball high enough, it will fall into the nest", "the one who hits the ball and falls into the nest wins", "when the ball moves, it is suitable to fly, tilt or rotate according to the location of the nest", "there are many programs to hit it standing or kneeling". These records vividly show that when a person is playing, he can only stand up and hit the ball high, and the ball that he has hit will slide in an arc in the air. Only when he has to cross the "obstacle" and fall into the nest, can he win. Like today's golf competition, there were different ways to hit the ball, such as side spin ball, inside and outside spin ball and so on. Moreover, in addition to the standing stroke, there is also the kneeling stroke. There are many kinds of postures.

Site requirements

(1) The land use should meet the characteristics and technical requirements of golf entertainment activities, and should choose the section with convenient transportation, beautiful environment, abundant green vegetation and no pollution.

(2) In addition to the main golf course, the golf course should also include the training ground, club hall, logistics service, management office, parking lot, etc. when necessary, it can also be equipped with vacation residential facilities, swimming pool and other entertainment facilities, etc.

(3) The golf course should have open lawn. Generally, it should be set in Hilly and gentle slope area, covering an area of about 65000 ~ 70000 square meters. The height difference of the ground at the fairway should be 10 ~ 20m.

(4) A regular court should be divided into 18 fields of different sizes and shapes, each consisting of a tee, fairway, green and hole. The distance from the tee to the hole is 548m. The total length of the standard course ranges from 5943m to 6400m, and the width varies. There should be boundary signs around the stadium, and boundary stakes should be set in key areas. Each site covers an area of 3-3.5 square meters.

(5) The tee off table is the lawn for tee off. There are two ball marks on the table, about 4.5m apart. The line between the two marks is called the tee off line. The general area of tee off table is 30 ~ 150 square meters, which is about 0.3 ~ 1.0 m higher than the surrounding surface. The surface of tee off table is pruned short grass, which has a certain hardness and smooth surface. Generally, there are two kickoff tables in each hole for male and female players. If it is used for formal competition, a third kickoff table should be added. The hole should be higher than the tee, but not more than 20m

(6) The green is the area where the hole is located, and its plane is mostly in a free shape similar to a round or oval shape. The surface of the green is planted with high-quality lawn, and it is trimmed and compacted, with slight gentle slope ups and downs, so that the ball can roll unimpeded on the field.

(7) From the tee to the green and between the holes is a flat fairway, the minimum width of which is 30m, generally 40 ~ 50m, planted with short turf. Outside the fairway is a rough area. Close to the fairway, there is a slight rough area 2 ~ 3M wide, i.e. there are short cut weeds, and the outer side is a severe rough area, i.e. natural grass or forest, during which it is difficult to shoot

(8) The basic equipment of golf includes ball, club and tee. The ball is made of colloidal material, with a diameter of no less than 4.16cm and a weight of 45.93g. There are two kinds of batting rods: wooden rod and iron rod, with five and nine types of length respectively. The length of the club is 0.91 ~ 1.29M. In order to increase the interest of batting and enrich the landscape of the venue, sand pits, ponds, streams and other obstacles can be intentionally set up in the venue.

(9) Reasonable layout of different lengths of fairway, fairway length is generally calculated according to the standard number of strokes, men's 3-5 strokes, women's 3-6 strokes. Generally, there are 4 holes in pole 3, 10 holes in pole 4 and 4 holes in pole 5.

Material Science

Golf ball is made of rubber solid ball, table

Chinese PinYin : Gao Er Fu