## Flight and rotation of a tennis ball

With the help of a tennis player hitting may send the ball over the net in a different direction, to tell him a different speed and give it a particular rotation. The speed of the ball is dependent primarily on the force of impact. The latter, in turn, depends largely on the speed of the missile toward the ball and the speed of approaching her ball. The higher the speed, the force of the impact may be greater and the faster will fly after hitting the ball. As the ball approaches the player at a rate that is independent of the latter, to regulate the power of retaliation may be primarily due to changes in the speed of a rocket. In addition, the force of impact also affects the ability to use the weight of his body. It is possible, provided that when the ball is hit by body weight moves in the impact direction.

In most cases, when hitting a tennis ball gets not only the progressive movement but also rotational. If the rotation speed of the ball is negligible, the rotation does not significantly affect the flight and bounce of the ball. Most rotational speed so much influence on the direction and speed as the flight and bounce of the ball, the technique most tennis strokes provides for mandatory registration of this factor.

The position of a tennis ball rotation axis can be different. When striking the ball from left to right and usually receives around the rotation about the horizontal axis. If after hitting the ball rotation is directed towards its flight, then produced hit called torsion. Conversely, the impact, in which the rotation of the ball is directed in the opposite direction of its flight, called sliced kick.

After hitting the ball flies twined up the steeply curved trajectory and bounce high and fast. The rotation of the ball, causing its rapid decline, tennis player helps keep the ball within the area, even in cases when the ball flies at a high speed. Torsion impact surface missiles string slides along po6erhnosti ball forward and upward, thereby largely inform and ball spin.

Ball rotation speed affects the sharpness of his flight. The rotational speed is, the smaller the speed of flight, meaning that part of the force takes to create a rotation of the ball and only part of the force creates a translational speed.

Reducing the speed of flight of the ball especially true with shredded impact. Therefore, to create a fast-paced game should not give the ball a considerable rotation.

Besides twisted and cut strokes and strokes are distinguished as flat. When they string surface missile at the time of rapprochement with the ball moving precisely in the direction of impact and so the ball flies almost without rotation. The ball is sent flat. Stroke, usually it has great speed, flying through the flat trajectory and quickly bounces. To create a fast-paced game is best to use flat strokes since after them the ball flies at a higher rate.

## The visual perception of the ball

Movement tennis player must be extremely accurately aligned with a flying ball. Therefore, continuous monitoring of the ball is the most important prerequisite for the proper implementation of strikes. Most clearly the ball must be visible at the time drawing on it blow. The need for continuous monitoring of the ball connected with the anatomical and physiological characteristics of our eyes. The eye has a property accommodation, thanks to which we may well see objects that are close and relatively far away from us. But if we clearly see objects that are close to us, things that are far away will be visible at the moment is relatively bad. Equally clearly see objects that are near and far from us, it is impossible. Since the game is especially important to hit the ball, it becomes clear that it is the ball and needs to see more clearly. Seeing clearly the ball at the same time, the enemy, the site, and the grid can not be said for the anatomical and physiological characteristics of our eyes. The ball is clearly visible to the player, the more likely that it will be broken, as necessary, the middle of the string surface missiles.

## Getting around the site and preparing for shocks

Tennis performs most punches during movement on the court. From the characteristics of movement to a large extent depends on the quality of impact. Each stroke requires careful preparation and, above all, the correct approach to the ball. With all the forehand movement of the ball and begins with the left foot and leg is the same next step before hitting the ball. Approach the ball at all the bumps on the left begins the other way around, with the right leg and the last step is also performed right foot.

Simultaneously with the movement of the ball and begins to swing a tennis player, t. E. Removes his hand with a missile in the direction (to the right when hitting the right and to the left when struck on the left). Swing made simultaneously with the rotation of the torso. Tennis starts as soon as it determines the direction of the enemy strike. When approaching the site with a missile strike arm taken out toward the ball. Before contact with the ball, a rocket moves in a straight-line path.

Navigating the site is carried out by several steps elastic bent legs. By the time the ball is hit by the legs are bent more than the lower point strikes the ball. During the stroke in considerably lower legs are bent at the same time to avoid unnecessary torso and to keep rocket rectilinear motion toward the ball.