The task, in my opinion, is trivial, it's just that my answer does not agree with the fact that at the end of the textbook, I decided to ask for help. The condition of the problem (from the problem book Zaikin, Ovchinkin, Prut):
The athlete pushes the shot from a run. Assuming that the speed of the shot relative to the athlete at the time of the throw is equal in magnitude to the take-off speed, find the angle at which the shot should be released with respect to the ground so that the flight range is maximum. The height of the athlete himself is not taken into account.
I solve it again, on the forehead:
let - the speed of the athlete (directed along the axis)
- speed of the core relative to the athlete (directed at an angle to the horizon)
= = (by condition)
It is clear that the resulting speed is the vector sum of the above two speeds. The flight time depends only on the vertical component of the speed, and this vertical component, in turn, is contained only in the speed of the core relative to the athlete, so the dependence of the coordinates on time will be as follows:
The flight time is found from the equation for the vertical coordinate:
I substitute the resulting expression into the formula for calculating the horizontal coordinate:
I take the derivative with respect to:
To find the maximum value, i.e. extremum, you need to equate this derivative to zero, hence
Then the angle turns out to be equal, but the answer is indicated. I don't understand where is the mistake?
2. Introduction
3. The history of the development of the shot put
4. Shot put technique
5. Exercises and games when teaching shot put technique
7. References
Introduction
Shot put is an athletics exercise and is one of the types of throwing. Throwing, in turn, is an exercise of a speed-strength nature, their goal is to move certain projectiles in space over as long distances as possible. Any type of throwing is characterized by explosive, powerful efforts. The classification of throwing depends on the method of holding the projectile and the run. The shot put is performed from a jump or turn by pushing the projectile with the hand from the shoulder. As a result of many years of improvement by various athletes of the shot put technique, at present, pushers achieve high results. Shot put can be taught quite quickly, but for the preparation of an athlete high level, which will show high sports results, long-term, purposeful, hard training is needed.
1. The history of the development of the shot put
There was a shot put from folk games- pushing weight (logs, weights, stones). As a sport, shot put appeared in the middle of the 19th century. It was then, in 1839, that the result was first documented. This was the result of the Canadian T. Karradis, who pushed the shot to 8 m. 61 cm. The first record in the shot put belongs to the Englishman Fraser and is equal to 10 m 62 cm and was set in 1866. In 1868, an indoor shot put competition was held in New York City.
In the 19th century, the shot put technique was very primitive. The projectile was pushed almost from the spot, after preliminary swaying. Soon attempts began to be made to use the entire space of the circle for preliminary movements. First, the athlete, having taken a position at the back of the circle, made jumps on one leg almost to the front edge of the circle, after which the shot put was performed. Thanks to different options movement in a circle, a method of pushing the core sideways in the direction of the projectile flight with an energetic movement of a straight line or a little bent leg. This method was used until the 50s.
The most common shot put competitions were in the UK, and later in the USA. At the beginning of the twentieth century, the most famous shot putter was an American, Olympic champion R. Rose. His height exceeded 2m, and his weight was 125kg. He set his record in 1909, it was 15m 54cm, and held for 19 years. Only in 1928. The proportionally built German athlete E. Hirschfeld was the first in the world to push the shot at 16.04m. Until the 70s, the world record increased, most often thanks to American athletes. In the 30s - D. Torrance, nicknamed "man-mountain" pushes the shot at 17m 40cm, his height is 2m, and his weight is -135kg. For a long time there was an opinion that shot putters should have a large muscle mass and great growth, no one could have imagined that an athlete weighing 85kg could beat D. Torrance's record. This was done by the Negro Ch. Fonville, who had an outstanding speed in the shot put. In the 40s - K. Fonville (17m 68cm) and D. Fuchs (17m 95cm). In the 1950s, P. O, Brian (19m 30cm) pushes the core for the nineteen-meter mark. In the 60s, D. Long (20m 68cm) overcomes the 20-meter mark for the first time, and R. Matson improves this result, bringing it to 21m 78cm. In 1976, two weeks before the Olympics, the Russian athlete A. Baryshnikov for the first time takes the world record from the Americans, pushing the shot at 22 meters. Moreover, he uses a completely new shot put technique, not from a jump, but from a turn.
Soviet shot throwers lagged behind American and European athletes for a long time. In 1928, the Soviet athlete D. Markov for the first time pushed the core to 13m 09cm, at that time the world record belonged to E. Girshfeld and was equal to 15m 79cm. Later, this gap was reduced by the Estonian athlete H. Lipp. In the 50s, his all-Union record was 16m 98cm, and the world record was 17m 95cm. In the late 70s - early 80s, Soviet athletes became leaders in world sports.
At present, the world record in the shot put belongs to the American R. Barnes - 23m 12cm, and for the first time the German W. Timmerman overcame the 23-meter line in 1988. Barnes' record was set in 1990.
In the 50s, there were significant changes in the shot put technique. The basis of the new method was the technique used by the American athlete Oh, Brian. It was he who began to push the core with starting position with his back to the direction of the projectile flight, increased the inclination of the torso and introduced a rotational movement in the projectile ejection phase. This technique has been continuously developed and improved by other athletes. Search best technology continue constantly.
Much later than men, women began to take part in shot throwing competitions. The first official world record belonged to the Austrian athlete H. Kepll in 1926 and was 9m 57cm. In 1938, for the first time, women shot put at the European Championships, and since 1948, women began to participate in this form at the Olympics. Since the 40s, thanks to the achievements Soviet athletes, the growth of world records began: T. Sevryukova (14m 59cm), G. Zybina (16m 76cm), T. Press (18m 59cm), N. Chizhova (20m 43cm). Since the late 60s, athletes from the USSR and the GDR have achieved the best results. The world record belongs to the Soviet athlete N. Lisovskaya and is 22m 63cm (1987).
2. Shot put technique
The shot put technique has undergone changes throughout its history. There was a push from a place, a push from a step, a push from a jump, a push from a jump from a side position, a push from a jump from a standing position with the back, a shot put from a turn. At present, the jumping shot put technique is the most common, only a few throwers use the turning shot put technique.
Shot put is made from a running start, with one hand from the shoulder. At competitions, the shot put is made from a circle with a diameter of 213.5 cm to a sector equal to 40. A segment is installed in front of the circle. It is forbidden by the rules to separate the projectile from the neck in the preliminary run-up (jump, turn), and in the final effort to throw the shot. After the release of the projectile, the thrower must take a stable position in the circle, get out of it backwards, only then the attempt is counted. When pushing, it is forbidden to take the core beyond the line of the shoulders.
In competitions, cores of a certain weight are used: 3kg, 4kg, 6kg, 7kg 257gr, depending on the gender and weight of the athlete. The core weighing 7.257 kg is used in competitions for men and older boys, weighing 5-6 kg for younger boys, weighing 4 kg for women, older girls and boys, weighing 3 kg for younger girls and girls.
The range of the cannonball is measured from the inner edge of the segment to the point of impact of the cannonball. It depends on the initial speed at the time of departure, the angle of departure, and the height of the release of the projectile from the thrower's hand.
The shot put technique consists of two main parts: the preliminary acceleration with a jump or turn and the final movement. Preliminary acceleration is conditionally divided into the following phases: holding the projectile, starting position, preparation for the jump (swing and grouping), acceleration - jump. It is this part of the technique that creates the initial speed of the core and the conditions for the active implementation of the final effort.
The final movement consists of the final effort and balance after the impact of the projectile. All parts and phases of the shot put technique are interconnected, follow one from the other in a logical sequence, which creates a single movement.
The generally accepted way of running in the shot put is the jump on the leg, which is the same name as the pushing arm. The run-up in this case is the phase of movements from the beginning of the swing with the left leg for the jump until the moment of landing on the right leg. This method of takeoff, due to the small area of the circle, makes it possible to develop only an insignificant speed of movement of the body with the nucleus.
In the initial position, the core is held on outstretched fingers right hand. Index, middle and ring fingers slightly apart, the thumb and little finger hold the ball to the side. Beginners can place the nucleus lower on the main phalanges of the fingers, for qualified athletes - on the main and middle phalanges.
The core should lie on free fingers. If in beginners, under the weight of the core, the hand or fingers extend significantly, then it is necessary to counteract excessive extension by muscle tension.
Before the jump, the core is held at the neck, in the region of the supraclavicular cavity. The elbow is drawn away from the body, and the forearm is held approximately in the direction in which the final effort is made. In the initial position, the pusher stands in a circle, with his back to the direction of pushing. The elbow at this time is retracted forward - to the right. Differences are possible, which depend on the ratio of the length of the shoulder and forearm, the strength of the athlete's muscles and the starting position. It is forbidden by the rules to keep the core on weight.
The athlete occupies the starting position at the rear part of the circle in the direction of pushing. The athlete stands on the right leg. Body weight is evenly distributed on the right foot. The left leg is set back about one foot and touches the ground with the toe. The body is straightened, the pelvis is slightly forward. The left hand is raised up and slightly laid aside, this position helps to maintain the balance of the athlete. The head is in a natural position, the gaze is directed straight ahead.
Before the jump, the thrower from the starting position smoothly tilts the body forward, at the same time raises the left leg until the body approaches the horizontal position. The right leg is slightly bent at the knee joint, and the weight of the body is located on the entire foot. The position of the head in relation to the body does not change. During the movement, the thrower must maintain a stable balance.
At the moment when the torso approaches the horizontal position, the next phase begins - “grouping”. In this phase, all parts of the body are grouped towards the right leg, which is bent at the hip, knee and ankle joints to a position where the angle of flexion at the knee joint will be almost 90 degrees. The body leans forward until the chest touches the thigh of the right leg. The degree of inclination of the torso and the angle of flexion of the right leg depend on the development of the muscles of the legs and torso of the athlete, on his flexibility and mobility. The left hand goes down and hangs freely. trunk, and especially shoulder girdle tense.
Time of flight of the bullet to the target: | ||||||||||||||||
X = v 0 τ; τ = | ||||||||||||||||
Change in the vertical coordinate of the bullet during the flight τ: |
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1.25m; |
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26. A body is thrown with a speed v0 = 10 m/s at an angle α = 600 to the horizon. Determine the speed of the body at the top of the trajectory.
1. A body thrown into the earth's gravitational field with an initial velocity v0 directed at an angle α to the horizon will move along a curvilinear trajectory lying in a plane perpendicular to the earth's surface. It is essential to note that the movement proceeds at constant acceleration g in absolute value and direction. This makes it possible to decompose the curvilinear motion
into two simpler ones: uniform along the horizontal axis because gx = 0 and accelerated along the vertical axis, where the gravitational acceleration manifests itself in two ways.
Rice. 26. A body thrown at an angle α to the horizon
2. The movement of the body under study relative to the vertical axis from the initial point O to point C is equally slow, and from point C to point B is uniformly accelerated with the acceleration of free fall g. At the initial moment of time
at t = 0 we have: x0 = 0, y0 = 0, v0x = v0 cosα , v0y = v0 sinα , ax = 0, ay = − g.
3. For projections of speed at any time, for example, at point M,
The modulus of the velocity vector is defined as | ||||||||||||||||||||||||
V 0 2 cos 2 α + | (v0 sin | α − gt ) 2 = | v0 2 cos2 α + (v0 2 sin2 α − 2v0 sinα gt+ g2 t2 ) , |
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v0 2 (cos2 α + sin2 | α ) − 2v0 gt sinα + g2 t2 . | |||||||||||||||||||||||
We determine the position of the velocity vector using the properties of the direct |
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angle triangle built on the velocity vector and its projections | ||||||||||||||||||||||||
sin α − gt | ||||||||||||||||||||||||
tg β = | , β = arctan | |||||||||||||||||||||||
v0 cosα | ||||||||||||||||||||||||
We write the equations of motion using the features of the uniform |
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displacement of a point horizontally and uniformly accelerated vertically | ||||||||||||||||||||||||
x(t) | V0 t cosα , | |||||||||||||||||||||||
V0 t sinα − gt 2 . | ||||||||||||||||||||||||
y(t) | ||||||||||||||||||||||||
The time of lifting the body to the upper point of the trajectory C is determined using |
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using the second equation of system (1) under the condition: vy = 0 | ||||||||||||||||||||||||
v0 sinα − gtC = 0, tC = | v0 sinα | |||||||||||||||||||||||
τ = 2t C = | 2v 0 sin α . | |||||||||||||||||||||||
When substituting the flight time τ into the first equation of the system (3.38) |
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get the maximum throw distance | ||||||||||||||||||||||||
xmax= | 2v2 sinα cosα | v2 sin 2α | ||||||||||||||||||||||
10. From the last equation, in particular, it follows that, other things being equal, the maximum throw distance will take place atα \u003d 450, because in
in this case 2α =π /2, sin 2α = 1.
11. The maximum lifting height is determined by substituting the time from equation (6) into the second equation of system (4)
sinα | sinα | g v2 sin2 | ||||||||||||
ymax= | v2 sin2 | |||||||||||||
12. The trajectory equation is obtained by eliminating time from equations (4). From the first equation
v0 cosα | |||||||||||||
when substituting this value of t into the second equation, we get | |||||||||||||
y=v | sinα | − g | Xtgα − | ||||||||||
v0 cosα | 2v0 2 cos2 α |
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2 v0 2 cos2 α | |||||||||||||
13. If we introduce the notation: tgα = a, | (2v0 2 cos2 α ) = b , then the equation of tra- |
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vectors will take on a more classifiable form | |||||||||||||
y = ax - bx2 . | |||||||||||||
14. The above analysis shows that at the top of the trajectory the vertical velocity component vanishes, i.e. vC=vx
vC \u003d vx \u003d v0 cosα \u003d 10 0.5 \u003d 5m s;
27. The athlete pushes the shot with an initial speed v0 = 15 m/s at an angle α = 450 to the horizon. Determine the flight time of the nucleus and the time it takes to rise to the highest point of the trajectory.
x(t) = v | t cosα , | |||||||||||||||
y(t) = v0 t sinα − gt 2 . y(t) = 0; | v0 t sinα − | 2 = 0; | ||||||||||||||
− v0 t sinα = 0; | 2 − | t sin α | 0; tΣ | sinα | ||||||||||||
1.06c; | ||||||||||||||||
28. A disk thrown at an angle α = 450 to the horizon has reached greatest height h = 15 m. Determine the range of the disk.
1. Disc flight time:
− v0 t sinα = 0; t2 | t sin α | 0; tΣ = | sinα | ||||||
2. Disk initial speed:
sinα | sinα | g v2 sin2 | v2 sin2 | ||||||||||||||
2g2 | |||||||||||||||||
m; | |||||||||||||
sin2α | |||||||||||||
3. Disk flight range: | |||||||||||||
xmax= | 2v2 sinα cosα | v2 sin 2α | |||||||||||
29. Find the height of the flare fired at speed v 0
= 20 m/s at an angle α = 60 0 to the horizon.
ymax= | v2 sin2 | 15m; |
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30. A stone thrown at an angle to the horizon reaches its maximum height h = 45 m. Find the flight time of the stone.
v2 sin2 | v0 sinα = 2gh; |
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t Σ = 2v 0 sin α | ||||||||
31. The mass of a concrete block having the shape of a rectangular parallelepiped is equal to m1 = 6 kg. What will be the mass of the block if its first side is doubled, the second - by 1.5 times, and the third is reduced by 3 times?
m1 = ρ (a b c) ; | ||||||
m = ρV; | m1=m2=6kg; |
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1.5b | ||||||
= ρ2a | ||||||
32. Two cubes are made of the same material. The side of the second cube is 2 times larger than the second. Compare the masses of the cubes.
m = ρV; | m 1 = ra | ||||||
m2 = ρ (2a) | |||||||
33. A skier with a mass m = 60 kg, having a speed v0 = 10 m/s at the end of the descent from the mountain, stops after τ = 20 s after the descent. Determine, neglecting air resistance, the magnitude of the friction force.
1. Acceleration of the skier during his movement after the descent:
2. When moving from the end of the descent to the stop, one external force acts on the skier in the direction of movement - the friction force, which provides braking. Newton's second law equation in projection onto the horizontal axis:
Fμ = ma= 60 0.5= 30 H;
34. A car with a mass m = 1800 kg, moving from a state of rest along a horizontal path, after τ = 10 s reaches a speed v = 30 m/s. Determine, neglecting the resistance to movement, the traction force of the car.
1. Vehicle acceleration during acceleration: | |||||||||
7. The equation of Newton's second law in projection on the direction of motion:
F = ma= 1800 3= 5.4 kN;
35. A body of mass m = 100g moves along the axis OX, the change in the projection of velocity in time is given graphically. Determine the value of the force acting on the body at the time τ = 2 s.
| a |= | |||
9 − 3 | 0.2H; | Rice. 35. Projection dependency |
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speed from the time of movement of the body |
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1. Modulus of the resultant: r
R = F1 2 + F2 2 + 2F1 F2 cosα = 50− 50 0.5= 5H; 2. If (i; F2 ) = π 6, then (i; R) = π 2 .
37. Forces F1 = 6 N and F2 = 8 N are applied to one body. The angle between the lines of action of forces is α = 900 . Body weight m = 2 kg. Determine the acceleration with which the body is moving.
1. The resultant force: | ||||||||||
2F F cosα ;α = 900 | 36+ 64= 10N; |
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2. Body acceleration:
∑ F i | ||||||||||||||
∑ Fi = mar ; | ||||||||||||||
38. The bar descends from an inclined plane, length L = 15 cm during τ
= 0.26 s Determine the resultant of all forces acting on a bar of mass m = 0.1 kg during its movement if the initial speed of the bar is zero.
1. Acceleration of the bar: | ||||||
2. The resultant force acting on the bar:
0.44H; |
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10− 2 |
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39. A projectile of mass m = 2 kg flies out of the gun barrel in a horizontal direction with a speed v = 400 m/s. Determine the value of the resultant of all forces, considering it constant, if the length of the trunk L = 2.5 m.
The time of movement of the projectile in the barrel of the gun: | |||||||||||||
v; L= | 1.25 10−2 s; |
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The resultant force: | |||||||||||||
R = ma = m | v 2 \u003d 2 1.6 10 5 | 6.4 103 N; |
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40. Two balls with radii R1 = 0.2 m and R2 = 0.3 m touch each other. How many times will the gravitational force between the balls change if one of the balls is moved x = 100 cm?
m1 m2 | |||||||||||||||
(r1 | |||||||||||||||
R2) | |||||||||||||||
0,52 | |||||||||||||||
X ) 2 | |||||||||||||||
41. The distance between the planet Neptune and the Sun is 30 times greater than the distance between the Earth and the Sun, the mass of Neptune is 15 gas more than the mass of the Earth. How many times greater is the attraction of the Sun to the Earth than the Sun to Neptune?
F \u003d Gm H m C; | ||||||||||||||||||
F=G | ||||||||||||||||||
42. How will the force of gravity acting on the rocket change when it rises vertically to a height equal to two radii of the planet?
F=G | ||||||||||
F=G | ||||||||||
(R+ 2R) | ||||||||||
43. How will the force of gravity acting on the spacecraft change if at first it was at a distance of three earth radii from the surface of the planet, and the mote was only one radius?
(3R + R) 2 | |||||||||
F=G | |||||||||
(2R) | |||||||||
44. Determine the acceleration of gravity on a planet whose mass is 200% greater than the mass of the Earth, and the radius is 100% greater than the earth's. Acceleration of free fall on the Earth take g 10 m/s2.
mg = GmM | ; g = GM Z ; | |||||||||||
RZ 2 | RZ 2 | |||||||||||
3MZ | g X = 3 ; | 3g=7.5 | ||||||||||
4R3 2 | ||||||||||||
45. Suppose that the radius of the Earth has decreased by 3 times. In this case, how should the mass of the Earth change in order for the acceleration of free fall on its surface to remain the same?
mg = GmM | ; g = G | |||
M X 2 ; MX = M ;
46. The spacecraft moves around the Earth in a circular orbit of radius
som R = 3 107 m. Take the mass of the Earth equal to M = 6 1024 kg. Determine the speed of the spacecraft. G RM 2 = G
; v= | 6,67 10− 11 | 6 1024 | |||||||||||
47. The first space velocity for a Mars satellite flying at a low altitude, v = 3.5 km / s. Determine the mass of the planet Mars, if its radius is
mustache R = 3.38 106 m.
; M= | 1,23 107 3,38 106 | ||||||||||
v 1= | |||||||||||
v1 = 3v2 ; | |||||||||||
v2= | |||||||||||
49. The mass of the satellite was increased by 4 times. How will the value of its first cosmic velocity change?
1. The condition for the satellite to be in a circular stationary orbit:
; v= | |||||||
2. The mass of the satellite is not included in the equation of the first cosmic velocity.
50. What is the period of revolution of the low-orbiting satellite of Mercury, the mass of which is M = 3.26 10 23 kg, and radius R = 2.42 106 m?
; v= | 6,67 10− 11 | 3,26 1023 | ||||||||||
v = ω R= | 2π R | 6,28 2,42 106 | 5,103 from 1.41 days; |
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Determine the stiffness of the system |
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two series-connected wires |
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tires with hardness k1 = 600 N/m and k2 = 400 N/m. |
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Rice. 51. Series springs | When connected in series |
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springs, their deformation will be different with |
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the same operating force, this is the |
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The measurement allows you to determine the total stiffness of the springs as follows:
x o= x 1+ x 2 | |||||||||||||||
k o= | k1 k2 | N . | |||||||||||||
k 1+ k 2 | |||||||||||||||
| 1 | x + k | 600N | |||||||||||||
53. A third spring is connected in parallel to two springs connected in series. What is the stiffness of the system if all springs have the same stiffness k1 = k2 = k3 = 600 N/m?
1. The rigidity of the serial connection
x o= x 1+ x 2= | |||||||||||||
k 1.2 | |||||||||||||
k 1,2= | k1 k2 | 600 600 = 300 N | |||||||||||
k 1+ k 2 | Rice. 53. Mixed connection of springs |
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3. The rigidity of the system of three springs: | |||||||||||||
k 1,2,3 | K 1,2+ k 3 | ||||||||||||
54. Under the action of the load, the wire lengthened by x \u003d 1 cm. The same load was suspended from the same length of the wire, but having a 2 times larger cross-sectional area. What will be the length of the wire?
ε 2 \u003d mg 2s; x 2 \u003d 2; x2 = 5 10 − 3 m;
55. On a rough horizontal surface lies a body of mass m = 1
kg. The coefficient of friction sang on the surface μ = 0.1. Determine the friction force between the body and the surface under the action of a force F = 0.5 N.1 x 1 on the body
1. The value of the friction force at the start of motion:
FTr \u003d μ mg 0.1 1 10 \u003d 1H; FTr > F,
therefore, the modulus of the friction force is equal to the force acting on the body at rest.
56. A body of mass m = 1 kg moves along a horizontal plane. A force F = 10 N acts on the body, directed at an angle α = 300 to the horizon. The coefficient of sliding friction is μ = 0.4. Determine the modulus of the friction force.
Rice. 56. Force of friction
FТр = μ N ;
N = mg+ Fy = mg+ Fcos600 ; Fr Tr \u003d μ (mg + Fcos600 ) ;
Fr Tr \u003d 0.4 (10 + 10 0.5) \u003d 15H;
57. The load is lifted on a rope: once evenly, the second time with an acceleration a = 20 m / s2. How many times greater is the tension of the rope in the second case than in the first case?
g + a | |||||||
M(g + a); | |||||||
58. A skydiver with mass m1 = 80 kg descends on a parachute with a steady speed v = 5 m/s. What will be the steady speed if a boy of mass m2 = 40 kg descends on the same parachute, assuming that the air resistance force is proportional to the speed of the parachute FR v?
m1 g= kv1 ; | ; v2 | ||||||||||||
m2 g= kv2 ; |
59. A bus, the mass of which with a full load is m = 15 tons, starts off with an acceleration a = 0.7 m / s2. Determine the traction force of the bus engine FT if the coefficient of resistance to movement r = 0.03.
1. Newton's second law in projection on the direction of motion:
FT = ma+ FR = ma+ rmg= m(a+ rg) = 1.5 104 (0.7+ 10 0.03) 1.5 104 H;
60. A bar of mass m = 0.5 kg is pressed against a vertical |
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wall with force F = 10 N. Friction coefficient |
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slip between the bar and the wall is μ = 0.4. |
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What magnitude of vertical force must be applied |
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live towards the bar in order to lift it with acceleration a = |
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2 m/s2? |
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Normal Communication Response: |
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Friction force: |
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F Tr | = μN = μF ; |
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Rice. 60. Accelerated rise | Newton's second law equation in projection |
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Shot put history
Shot put how kind athletics appeared in England in the middle of the 19th century. The prototype of the sports shot put is various folk competitions in throwing, pushing stones, weights, cannonballs, etc. The first unofficial record in the shot put (10.62 m) was registered in England in 1866. Already at that time, the mass of the projectile was set at 16 English pounds (7.257 kg), and the diameter of the pushing circle was 7 feet (2.135 m). The technique was primitive, the athletes did not use the entire area of the circle and pushed, jumping forward on one leg.
The search for the most rational shot put technique followed the path of accelerating the athlete's movements by lengthening the path of applying force to the projectile, increasing the power of the final effort. As a result, this led to the creation at the beginning of the 20th century. method of pushing the shot sideways in the direction of the projectile flight. Something like this was done by the two-time Olympic champion, ex-world record holder R. Rose (USA), whose highest achievement of 15.54 m (1909) lasted 19 years. Interestingly, until 1912, the champion was identified in the best attempt with a push from both hands, and even the amount of a push from both hands was determined - this was how the harmonious development of athletes was encouraged.
This version of the technique was actively used by shot putters for many decades and lasted until the early 1950s, when the traditional shot put method was further developed. P. O'Brien (USA), later a two-time Olympic champion (1952 and 1956), proposed starting preliminary acceleration from the starting position with his back to the direction of the projectile flight. This made it possible to significantly reduce the initial height of the projectile above the ground and thereby reduce the angle between speed vectors reported to the core in the phases of the initial and final acceleration. motor actions led to a significant increase in world achievements during this period, and the record came close to the 22-meter mark.
This milestone was overcome (1976) already with the help of a new version of the shot put. In this way, the Soviet thrower A. Baryshnikov for the first time pushed the shot at 22 m. The rotational method, or the “circular swing” method, is characterized by a higher starting acceleration speed. It allows you to more effectively use the preliminary stretching of the muscles of the body at the beginning of the final acceleration, as well as slightly increase the radius of its turn.
At the present stage of development of athletics, the method of "circular swing" among male athletes, oddly enough, is much more popular in the United States but compared to Russia and European countries. World record holder R. Barnes (23.12 m), like all the leading US male athletes (A. Nelson, K. Cantwell, R. Hoffa), used and use pro. Nevertheless, T. Majewski (Poland), a two-time Olympic champion in 2008 and 2012, uses a stepwise progressive version of the projectile acceleration technique. Thus, shot putters use both versions of the competitive exercise, since their practical significance is almost equivalent.
Shot put for women was included in the program of the Olympic Games only in 1948. A real triumph for Soviet athletes was a world record and a gold medal. Olympic medal G. Zybina (Helsinki, 1952) - In 1956 in Melbourne Olympic champion becomes T. Tyshkevich, and T. Press brings the world record to 18.55 m at the Olympic Games in Rome (1960) and Tokyo (1964) and becomes the Olympic champion. In Munich (1972), Seoul (1988) and Barcelona (1992), our athletes N. Chizhova, N. Lisovskaya, S. Kriveleva repeat the success of older shot putters. From 1987 to the present, the world record in shot put belongs to N. Lisovskaya (22.63 m).
The greatest achievements of men - shot putters of our country are associated with the victory of V. Kiselev at the Moscow Olympics (1980).
On the Olympic Games in London, the victory in men was won by Pole T. Maevsky (21.89 m), in women - an athlete from New Zealand W. Adams (20.70 m). Russian athlete E. Kolodko became the second.
Shot put technique
Shot put technique
Main article:Shot put - physical exercise speed-strength character with a pronounced explosive character muscle work. It is performed with a push of one hand from the shoulder after preparatory movements in a strictly limited space. According to the rules of the competition, in the preliminary acceleration it is not allowed to take the shot away from the neck towards the shi back, but in the final effort it is not allowed to throw the shot.
Currently, there are two directions in the shot put technique. The first is represented by various modifications of the traditional jump-and-forward variant of the core acceleration technique from the starting position, standing with your back to the side of the push. The second direction is connected with the new rotational method of accelerating the core, in which the rotation is performed as in discus throwing, and the final effort is carried out basically in the same way as after the jump. Since the first version of the shot put technique is more common and easier to learn, we will focus only on it.
The shot put technique consists of two main parts: the preliminary acceleration with a jump and the final movement. Preliminary acceleration can be conditionally divided into separate phases: holding the projectile, starting position, preparation for the jump (swing and grouping), acceleration (jump). The final movement consists of the final effort and balance after the shot is pushed out.
Core holding
Core holding
Before performing certain actions with the core, the athlete must be able to correctly and rationally hold it in his hand. The nucleus is held at the base of slightly spread fingers near the neck in the region of the supraclavicular cavity under the chin. Thumb and the little finger support the projectile from the side, while the elbow of the right hand (hereinafter it is understood that the pusher holds the shot in the right hand) is retracted somewhat to the side and forward. How stronger muscles hand and fingers, the more the core can be moved to the fingers, allowing better use of the elastic properties of the muscles. Free and comfortable holding of the projectile has a positive effect on the further actions of the athlete.
Starting position
The athlete is in the far part (in relation to the segment) of the circle, with his back to the direction of the shot put. The weight of the body is on the right leg, which is placed on the entire foot with the toe to the inner ring of the circle, the left is set back on the toe. The torso is straight, the right hand holds the projectile, the left is raised up and slightly laid aside, which helps to maintain balance.
Having concentrated, the thrower proceeds to perform the movement of the next phase - the swing.
backswing
From the previous position, the athlete makes a swing of the left half-bent leg back and up, slightly rising on the toe of the right and at the same time tilting the body forward and down. The head is lowered so that the gaze is directed 1-1.5 m forward from the toe of the right foot. In essence, at the moment of the highest point of the swing of the left leg, the thrower assumes the position of a “swallow”. It must be emphasized that this is not a static, but an intermediate posture that occurs during the execution of a dynamic movement. A significant torso tilt forward and down should not be allowed, and the swing movement must be performed without sudden accelerations and stops, because. All this can lead to loss of balance.
grouping
Having completed the rise on the toe and the slope, the athlete begins the grouping, which is understood as the compressed (low, collected) position of the athlete before the jump (acceleration). The athlete, as it were, “groups” all parts of the body to the right leg, which at the same time bends, and the left, in a half-bent position, is slightly behind the right. The body leans towards the right thigh and at the end of the grouping is in a horizontal position or slightly tilted forward, while the head is lowered. The left hand almost touches the ground, and the elbow of the pushing hand is to the right of the knee of the supporting leg. In the course of such a grouping, convenient conditions arise for performing a swing with the left leg and repulsion with the right, in order to actively advance the athlete in the circle.
Overclocking
In the progressive method, the acceleration of the "thrower-projectile" system is a jump, the purpose of which is to inform this system of a certain speed directed along the diameter of the circle to its front edge. In addition, it should be remembered that a good jump sets the necessary, most rational rhythm for the entire shot put. The difficulty of performing this phase is due to the fact that the thrower develops speed not only due to the efforts of the left (swing) and right (push) legs, but also due to the skillful use of inertial forces resulting from the fall of the athlete towards the segment. It is extremely important when performing the jump to achieve such a position that the transition from grouping to the jump goes unnoticed and these two elements merge into one movement.
The jump starts from a grouped starting position with a back-up swing of the left leg. At the same time, the athlete makes a repulsion (jump) with the right foot from the toe or with a roll over the heel, straightening the right leg, and quickly moving in the direction of throwing, passing into the unsupported phase, which should be as short as possible in time. This is ensured by the fact that the athlete quickly pulls the right leg under him and puts it in the middle of the circle.
It is extremely important that the thrower perform this movement quickly and naturally, while maintaining a “closed” position of the shoulders and a significant forward and downward tilt of the torso. The jump should be very low, as if sliding on the surface of the throwing circle. It is also necessary to ensure that the foot of the right leg at the moment of placing on the support is turned inward (to the left) in the direction of throwing at an angle of approximately 45 °.
Since in the unsupported phase the speed of movement of the “pusher-core” system does not increase, it is advantageous for the athlete to quickly place the left foot on the support at the segment with the toe turned to the left, in order to start a powerful final effort earlier, using the inertia of the body.
During the jump itself, the position of the shoulders does not change, and the pelvis turns significantly to the left, which creates tension in the muscles that rotate and extend the body. Thus, if at the start the axes of the shoulders and pelvis were parallel, now the axis of the pelvis is turned in the direction of pushing the projectile by about 90 °. At the same time, the weight of the body continues to remain on the right leg, the projection of the core on the ground should be slightly to the right of the right foot.
The speed of movement of the thrower in the jump reaches 2-2.5 m/s, the acceleration time is 0.60-0.50 s.
The final movement of the projectile begins from the moment the left foot is placed on the support with the onset of a two-support position. This part of the shot put technique is the most important and responsible, it contains the greatest increase in the speed of the shot (up to 80-85%).
The final effort begins with the rotation of the pelvis. The active rotational-translational movement of the pelvis is the key, creating overtaking of the projectile and contributing to the greatest tension in the muscles of the body. The rotation of the pelvis is ahead of the rotation of the shoulders. And the more active it is, the more the shoulders will lag behind and, therefore, the final effort will be more powerful and effective.
In the future, the thrower, by moving the left hand forward and upward (still leaving the right shoulder and arm with the shot behind!) Performs a “taking on the projectile”, which continues until the body turns sideways in the direction of throwing. In this position, the left arm and shoulder are above the right shoulder, and the core should be as low as possible (its projection passes through the right knee, closer to the right foot), which increases the path of impact on the projectile.
Exercises to help master the shot put technique
The final part of the final effort begins with a very quick turn to the left with the chest forward and up, while turning both legs at the same time. At this moment, the movement of the pelvis stops, and the shoulder girdle continues to turn to the position of the chest in the direction of pushing the nucleus. At the same time, the legs are vigorously unbent, performing an upward lifting movement. It should be noted that in order to increase the effectiveness of the final effort by counter straightening of the left leg, the athlete stops the movement of the lower parts of the body. This allows, on the one hand, to transfer more movement to the body and arm with the projectile, and on the other hand, to stay in the circle.
Head position is important. From the moment the left leg is set, the gaze is gradually shifted up and forward in the direction of throwing, and a slight tilt of the head back contributes to an increase in the extensor reflex.
As a result of all these actions, the final part of the final effort is performed by a whip-like movement, first with the body, and then with the arm and hand, and coincides in time with the athlete's kicking off the circle with his feet. It is important that the legs do not come off the ground until fully extended. The straightening of the right arm is combined with the abduction of the left arm back and down, without lowering the left shoulder. The core should leave the hand as high as possible - above the segment or, even better, behind the segment.
After the nucleus takes off, an active permutation of the legs is carried out by jumping - the right leg is placed at the segment, and the left leg is retracted. This allows the thrower to take a stable position and not leave the circle.
All actions of the thrower are performed rhythmically, together, reaching the greatest speed in the final effort. Suffice it to say that the movements of the final effort take less than 0.4 s in time.
As for the total length of the nucleus path (2.5-2.7 m), it is largely determined by the difference in the height of the position of the nucleus at the beginning and at the end of the ejection. For the strongest athletes, this difference is 1.1-1.2 m, and at the time of departure, the core speed exceeds 13 m/s.
The sequence of problem solving when teaching shot put technique and their methodological orientation
Task 1. Create an idea of the shot put technique among those involved
Task 2. Teach holding and pushing the nucleus
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Applied means |
Guidelines |
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a) Explanation and demonstration of holding the projectile and the performance of this element by those involved |
To avoid injury, make sure that those involved do not hold the core at the ends of their fingers. |
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b) In i.p. stand legs apart juggling the shot, throwing it from hand to hand, pushing the shot down |
Exercises are performed in order to better feel the weight and inertia of the projectile. When performing the last exercise, the left hand holds the core from below, the right hand - from above. |
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c) Pushing a shot or medicine ball from the chest with both hands from the position of the legs apart, the projectile in front of the chest, elbows to the sides. The same, from the semi-squat position, from the position left leg ahead |
Pay attention to the fact that the arms, when pushing out, do not outstrip the extension of the legs, and the hands straighten outward |
Task 3. Teach shot put from a place (final effort)
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Applied means |
Guidelines |
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a) I.p. - leg stand apart with the left side in the direction of throwing, the left foot on the support inside, right - at a right angle, body weight on a bent right. The left hand "closes" the direction of the push, the right hand imitates holding the core. Imitation of the basic movements of the final effort |
Imitate the following movements-elements: a) bringing the right thigh inward (to the left) with the heel turning up and out to create a prerequisite for overtaking the projectile by a “turning” movement of the pelvis in the direction of throwing. The left arm moves backward with the elbow, helping to perform the "capture of the projectile"; b) by sequentially turning the chest in the direction of throwing, emphasize the position of the “stretched bow”, and at the same time shifting the weight of the body onto the straightened left leg, imitate the pushing of the projectile with an active movement of the right hand |
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b) I.p. - too. Perform the previous exercise without and with the projectile by “adding” active movements (“lifting”) with the legs and a whip-like movement with the torso |
First, study the movement at low speed in full amplitude. If the movement is mastered correctly, the speed of its execution increases. The exercise is effective when its implementation leads the trainees to a motor understanding of the movement as a whole and makes it possible to feel the main links: the removal of the right thigh, then the pelvis, the movement of the left hand, stretching the muscles of the body, the "pressure" of the chest forward, the lag of the pushing arm and the supporting position of the left leg |
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c) I.p. - the same, but with a large bending of the right leg and a preliminary turn of the body to the right. Pushing the core forward and upward through a branch, bar |
Landmarks are used to direct efforts mainly upwards and somewhat forward, making the most of the strength of the legs, torso and arms. It is advisable to perform the exercise for two cycles: 1 - is engaged in I.P. with a grouping of a pushing leg; 2 - the projectile is pushed out. Make sure that the final force is applied to the projectile due to the whip-like work of the hand and fingers |
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d) Standing with your back to the direction of the push, perform a lunge with your right foot forward with a tilt (grouping) of the body and a slight abduction of the left leg back and up, “close” with your left hand. The shot put begins with the left foot lowered to the ground. The exercise is closest to the final effort made after the jump, especially activating the “pushing” (right) leg |
The main attention is drawn to: the correctness of grouping after a step in the opposite direction; dynamic performance of the movement without premature activation of the pushing hand; the duration of projectile escort and the absence of inclination of the left part of the body in the final effort, which is facilitated by raising the left shoulder and fixing the left hand |
Task 4. Teach the technique of jump run
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Applied means |
Guidelines |
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a) A story about the jump technique in the shot put and its demonstration |
The display is carried out in different planes in relation to those involved |
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b) Standing at the gymnastic wall facing it, grip from above arms folded for the crossbar at waist level. Make an active swing of the left leg up and back, followed by bringing it to the right (grouping). Perform a swing with the left leg back with the extension of the right and a jump on it |
It is necessary to achieve a correct idea of the position and movement of individual parts of the body when performing jump elements. The extension of the right leg should not cause a significant decrease in the inclination of the torso and rotation of the shoulders of the thrower to the left. |
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c) Jumps from a standing position in an inclination forward on a slightly bent right leg with the left leg stretched back. The same, with the help of a partner who supports the left leg of the practitioner and easily pulls it, directing the jump horizontally towards the leg extended back |
It is advisable to make the first jumps short. Make sure that the foot of the right foot passes close to the ground during the jump and is placed when landing from the toe. At the same time, it is brought under the body as far as possible without losing stability. Maintaining a “closed” position of the body and straightness of advancement in the jump will be facilitated if at this time the gaze is fixed on a landmark located a few meters ahead |
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d) I.p. - stand on the right leg, the left one is freely set back, the arm of the same name is at the top. Imitation of swing, grouping, jump and subsequent "capture" of the projectile. Same with kernel |
Perform the exercise both outside the circle and in the circle. Pay special attention to effectively swinging the left foot back and building stability from the moment of preparing for the jump to landing on a bent right leg and then quickly setting the left. For a better assimilation of the elements of the jump technique, it is advisable to stop, check the position of the legs, torso, etc. The presence of markings for setting the legs will speed up the mastery of the jump |
Task 5. Teach shot put technique in general
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Applied means |
Guidelines |
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a) I.p. - standing with your back to the direction of the push, performing a shot put in light conditions (shorter jump and lighter shot) |
At first, the length of the jump is 50-60 cm. As you master the non-stop transition from pre-acceleration to final effort, you can gradually increase the length of the jump and the weight of the core. The main attention should be paid to the coordination of movements, straightness of movement in a circle, maintaining balance in all phases, active influence on the projectile from the beginning of the jump to its release, the “explosive” nature of the final effort |
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b) Shot put from a jump from a circle to technique and result |
Control over the correctness and effectiveness of the integral movement is carried out by determining the difference between a jerk from a place and a jerk from a jump. Particular attention is paid to the implementation of a holistic movement in the right rhythm, to the active, coordinated work of the legs, torso and arms in the final effort while maintaining balance after the release of the core. |
Requirements for the technique of performing track and field events (propulsion systems)
- To be able to push the core from a place, standing sideways and with your back to the direction of pushing.
- Jump-like acceleration should be performed after a swing and grouping in the form of a slide due to a wide accelerated swing of the left foot back and active repulsion of the right. Pay attention to the coordination of movements.
- To move from the jump to the final effort seamlessly and without delay. By the end of the jump, the shin of the right leg is quickly pulled up with the turn of the foot and knee inward.
- Start the final effort by straightening both legs with turning the pelvis and torso with the chest forward and upward in the direction of the push; end with a powerful extension of the arm.
- Maintain a stable position after the push.
Exercises for self-mastery of rational technique
- In support, standing facing the wall, push off from the wall by bending and unbending the arms with active extension of the hands at the end of the movement. The same with one hand.
- Shot put from the chest with both hands from the position of the legs apart, the projectile in front of the chest, elbows to the sides. Unbending your arms, push the core up, forward-up. The same from the squat position, from the position of the left leg in front. The exercise is also performed with a stuffed ball and a stone.
- Pushing the core forward and upward with one hand from the starting position, facing in the direction of pushing, standing legs apart. The same, but adding movements of the legs and torso. At first, study the exercise at low speed, and use various landmarks for the correct departure angle.
- Pushing the shot from a standing position sideways to the direction of the push with a large bending of the right leg and tilting to the side, the same with turning the body when lifting on the left leg.
- Standing with your back to the direction of the push, pushing the shot from a place by directing efforts mainly up and somewhat forward, making the most of the strength of the legs and torso.
- Standing at the gymnastic wall facing it, grip from above with bent arms over the crossbar at the level of the belt. Squat on the right leg and make an active swing with the left leg, followed by bringing it to the right (grouping). Swing with the left leg with the extension of the right and a jump on it.
Common mistakes that occur when teaching track and field exercises and how to correct them
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Mistakes |
Remedy |
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1. In the jump, the thrower turns the pelvis and shoulders in the direction of pushing (“opens”) |
Running backwards. Imitation of a swing with the left foot from the position of the group, holding on to the gymnastic wall (make sure that the swing is made with the heel forward) |
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2. Thrower after acceleration comes to a too high position |
In the grouping position, pay attention to the fact that the chest almost touches the right knee. When imitating, pay attention to the greater bending of the right leg, and not to the lowering of the shoulders in the tuck. |
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3. Stop after jump |
Reduce the speed of the jump and start the final effort with an instant rotational movement right knee forward and rotational movement of the pelvis |
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4. Insufficiently active and incomplete extension of the legs during the final effort |
Pushing the shot up and forward to a landmark (tree branch or other objects). Follow the full extension of the legs, perform special jumping exercises to develop the strength of the leg muscles |
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5. Premature turning and lifting of the shoulders in the direction of throwing |
Pushing the shot from a place in two steps: first, move the legs, the pelvis, followed by a “whip” of the body and pushing the shot with the hand |
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6. Hand throw |
Raise the elbow of the pushing arm and direct efforts to the core at the angle of pushing (elbow follows the core) |
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7. Exit of the pusher from the circle during or after the push |
Light shot put, paying attention to the quick shift of the legs after pushing the projectile. Pushing from a reduced circle |