一、三种模型的主要特点1.轻绳轻绳或称为细线,它的质量可忽略不计,轻绳是软的,不能产生侧向力,只能产生沿着绳子方向的力。它的劲度系数非常大,以至于认为在受力时形变极微小,看作不可伸长。其特点是: First, the three main characteristics of the model 1 light rope Light rope or known as the thin line, its quality is negligible, light rope is soft, can not produce lateral force, can only produce a force along the direction of the rope. Its coefficient of stiffness is so large that it feels minimal to distort when stressed. Its characteristics are: