解读短道速滑运动员大幅度倾斜身体过弯的力学原理

MECHANICS FOR THE HIGH-DEGREE BODY INCLINATION OF SHORT-TRACK SPEEDING SKATERS WHILE PASSING THROUGH A CURVE

短道速滑运动员在弯道高速滑行过程中需保持身体大幅度倾斜,这一现象背后蕴含着经典的力学原理,是力学教学与实践中极为有价值的案例。本文通过对短道速滑运动员高速过弯时的运动学描述以及动力学分析来对短道速滑运动员大幅度倾斜身体过弯的力学原理进行解释。通过牛顿第一、第二定律以及实验观测来获得质点做匀速圆周运动时向心加速度的计算公式。借助动力学理论中的达朗贝尔原理在与运动员随动的非惯性系统中引入惯性力,通过力系平衡分析来探究运动员过弯时大幅度倾斜身体的必要性,并给出运动员过弯时身体倾角的计算公式,借助模拟赛道实验来验证相关的分析结论。通过讨论短道速滑运动员在比赛中根据既定战术和现场比赛情况随时变化的线速度以及内外赛道的切换需要来分析运动员在过弯时的各类运动学参数的变化,给出影响运动员高速过弯的关键因素。

Short-track speeding skaters need to maintain a high degree of body inclination while passing through the curve. Such phenomenon implies rich mechanics, and it serves as a valuable case for mechanics teaching. In this work we explain the underlying mechanics for the high-degree body inclination phenomenon through kinematical and dynamical investigation. We introduced the formulae for centripetal acceleration of a mass point in uniform circular motion through the first and second Newtown’s laws combined with experimental demonstrations. Based on D’Alembert’s principle, an inertial force was introduced to the noninertial system which is attached to the skater. We then carried out analysis on the necessity for body inclination during the curve motion. The mathematical formula for the body inclination angle was provided. The corresponding results were verified by a mini track experiment. We discussed the related parameters which depend on the linear velocity and radius of curvature that vary with the established tactics and the real match situation.Finally, the key factors were provided for the short-track speeding skaters while passing through the curves.