What is the diameter of a soccer ball? Task

It is round, made of leather or other suitable materials, and is generally made of 12 pieces of black pentagon fabric and 20 pieces of hexagonal fabric. The circumference of the sphere shall not exceed 70 cm (28 inches) and shall not be less than 68 cm (27 inches). The weight of the ball, at the start of the game, must not exceed 450 grams (16 ounces) and must not be less than 410 grams (14 ounces).

The air pressure of the ball, at sea level, is to atmospheric pressure (600 grams to 1100 grams per square centimeter to pounds per square inch). Replacement of a substandard ball If, during a match, the ball breaks or is substandard: Play is stopped.

Replace the standard ball, and at the point where the ball breaks, the falling ball restarts the game. If the ball is in the goal area at that time, the place where the ball falls is on the goal area line parallel to the goal line, closest to the position of the ball at the time the play was stopped. If the ball is broken or out of standard if it is not in play, such as a half-time kick-off, goal kick, corner, free kick, penalty kick or throw

Restart the game according to the rules. During the game time, the match ball cannot be changed without the consent of the referee.

"Universally celebrated" specifications.

The following is a comparison of the specifications and FIFA standards of "Celebration of the Whole World".

Circumference: "Universal": - centimeters FIFA standard: centimeters.

Roundness: The diameter of the ball is measured in 16 different places.

"Celebration of the whole world": maximum error FIFA standard: maximum error water absorption: the football needs to be pressed 250 times in water.

"Celebration of the whole world": zero weight gain FIFA standard: maximum weight gain of 10% weight. "Celebration of the whole world": 440 + - g FIFA standard: 420-445 grams.

**Performance: In the test, the ball was dropped from a height of two meters to the steel plate, which was repeated 10 times.

The height of the :* is between 143 and 149 cm according to FIFA standards: the difference between the highest and lowest** heights in 10 times is not more than 10 cm.

Pressure loss: Air pressure is measured after 3 days of inflation.

"Putian Tongqing": maximum pressure loss 10% FIFA standard: maximum pressure loss of 20% "Putian Tongqing" is not made of 32 balls sewn by hand, but is made of 8 balls thermally bonded, which has higher roundness and stronger water resistance.

Grooves: Grooves are used to reduce air resistance and improve lateral stability in flight.

Embossing: Embossing is used to provide extra grip, which in turn improves the control of the goalkeeper and other players on the ball.

No. 1 is 8cm in diameter

No. 2 is about 13 cm in diameter

The British framed the football specs.

Before 1872, there were no official rules for the size of football, and the size of the ball was varied. The British first thought of setting the size of the football, and in 1872 the FA stipulated that the circumference of the football must be between 27 and 28 inches (i.e. to the centimeter). In 1973, the weight of the soccer ball was regulated, between 410 and 450 grams, and the circumference was limited to 68 to 70 centimeters.

We know that football has always followed this specification until now.

The circumference of a standard soccer ball should not be longer than 70 centimeters and no shorter than 68 centimeters.

From this, it is estimated that its diameter is between centimeters and centimeters.

The weight is between 396 grams and 453 grams.

According to FIFA requirements, the circumference of a standard ball is between 68 5 and 69 5 cm, and the maximum and minimum diameter errors of the ball cannot exceed 1 5.

Standard balls

The rules of the soccer game regarding the match ball:

The ball shall be round, its shell shall be made of leather or other permitted material, and no material may be used in its construction that may injure the player.

The circumference of the ball must not be more than 71 cm or less than 68 cm. The weight of the ball, which must not be more than 453 grams or less than 396 grams at the start of the game. After inflation, the pressure should be equal to 0 6-1 1 atmospheres (at sea level), i.e. equal to 600-1100 grams'.

During the match, the match ball may not be changed without the permission of the referee.

According to this calculation, the diameter of the football should be between centimeters.

No. 3: For children to train and learn to use the ball.

No. 4: Kicks 5 or 7 players.

No. 5: Regular 11-player match ball.

Number 5 is a standard soccer ball with a diameter of about cm

A standard 32-piece soccer ball diameter is that the soccer ball is a polyhedron that satisfies Euler's formula f-e+v=2, where f, e, and v represent the number of faces, edges, and vertices, respectively.

Let the faces of the regular pentagon (black skin) and the regular hexagon (white skin) on the surface of the football have x and y respectively, then the number of faces f=x+y

Number of edges e=(5x+6y) 2 (each edge is shared by a piece of black skin and a piece of white skin).

Number of vertices v=(5x+6y) 3 (each vertex is shared by three skins).

From Euler's formula, x+y-(5x+6y) 2+(5x+6y) 3=2, x=12 is solved

So there are 12 pieces of black skin.

Therefore, there are a total of 12 5 = 60 ridges in the black skin, and these 60 edges are all sewn together with the white skin.

For white skin: 3 of the 6 sides of each white leather are sewn together with the black skin, and the other 3 edges are sewn together with the other white skins, so half of all the sides of the white skin are sewn together with the black skin.

Then the white skin should have a total of 60 2 = 120 edges, 120 6 = 20

So there are 20 pieces of white skin.

The standard diameter of a soccer ball is:

The standard for the circumference of a sphere prescribed by FIFA is centimeters.