Dynamic Characteristics And Application Research Of Ball Motion State Change In Table Tennis

Scientific explanation of the dynamic characteristics of table tennis state change,help coaches and athletes to effectively grasp the law of changes in the specific application of various technologies,help to improve the rationality of the use of technology,and help teachers to sum up and discover new technologies.In order to help athletes quickly improve the level of sports.The dynamic characteristics of ball motion state change in table tennis were analyzed by literature method,expert interview method,interdisciplinary research method and inductive deduction method.Conclusion:(1)When the upper spin ball is in the rising stage,the Mugnus force has a certain propulsive effect on the horizontal direction of the sphere,while the Mugnus force hinders the horizontal direction of the sphere in the descending period;during the whole flight,the Mugnus force accelerates the fall of the sphere(the lower spin ball is the opposite).Because of the viscous force,the rotation speed of the ball decreases gradually after the ball is off the plate and before touching the other side.(2)The greater the relative velocity of the collision point between the ball and the racket,the greater the force between them.That is,the greater the closing velocity along the tangent direction of the spherical collision point when the ball collides with the racket,the greater the friction force of the ball against the racket,and the greater the closing velocity along the vertical pat direction of the collision point when the ball collides with the racket.The magnitude of friction force determines the change of normal translational velocity along the direction of friction force,and the magnitude of positive impact force determines the change of rebound velocity along the vertical pat direction.(3)Friction force is the force acting on the surface of the sphere.The greater the friction force acting on the surface,the greater the torque and the greater its effect on the rotation of the sphere.When the swing speed is similar,the less impact component(within a reasonable range),the greater the torque and the relative rotation of the ball.(4)When hitting the ball at the same time,when hitting the ball with different rotation with the same beat type and swing speed,the direction of the combined velocity of the collision is quite different.(5)The rebound direction of the ball is more forward-down than that of the rising ball,and the forward component value of the closing speed level of the ball will be obviously smaller than that of the falling speed level.Therefore,when the angle of pat is similar,the ball is relatively "not easy to eat and turn ",and when the ball is rubbed out of the ball similar to the rising period,the flying distance of the ball forward will be relatively long.(6)In the form of upswing forward racket,the swing speed becomes larger or smaller in a moderate range,and the direction of the initial velocity of the ball after hitting is basically small.In this direction,the ball is relatively easy to fall back to the countertop.(7)When hitting back the high arc ball and the forward arc ball with the same speed,the spin sense of the high arc ball will be obviously higher than that of the forward arc ball.(8)In the rising stage,the in-stage twist can make the ball get the upward rebound trend,if do not avoid the strongest rotation area,the racket swing speed can not be less than the linear speed of the sphere,otherwise the bat must get off the net.Recommendations:(1)In the descending period,the angle of the pat should be more backward,otherwise it is relatively easy to rub the ball down the net.When rubbing the short ball,try to rub the ball in the rising period,and the ball can be rubbed shorter than the ball at the same time.If missed the opportunity,in the decline of the ball,should be moderately increased pat back angle.(2)When pulling up the ball,the swing direction should be more forward;when pulling down the ball,the swing direction should be more upward.If the direction of the ball is similar to that of the pull-up ball,the forward angle of the pat can be reduced appropriately,and the swing should be moderate to the top.(3)The ball should be hit as far as possible in the rising stage,when the ball's direction of motion is closer to the direction of the racket motion is better resultant force,at this time the racquet face can be fully forward,and can reduce the ball "leak" probability.If the rising period is missed,it is forced to catch the ball in the descending period(especially in the later period of decline).At this time,it is not suitable to make too much effort,which can reduce the forward angle of the pat and increase the forward impact to fight back.(4)For the highly rotating ball,twist the ball in the table in the rising period,if the downward spin is very strong,should also take the initiative to avoid the strongest rotation area,the ball can choose the side of the ball,the side from the front friction can not only make the ball forward power,but also can effectively avoid the strongest rotation area.