frictional ratio

例句：

1. 1.The frictional ratio of the material is critical for its performance.
   材料的摩擦比对其性能至关重要。
2. 2.In aerodynamics, understanding the frictional ratio between air and surface is crucial.
   在空气动力学中，理解空气与表面之间的摩擦比至关重要。
3. 3. The engineer used a formula to calculate the frictional ratio in the machine.
   工程师使用一个公式来计算机器中的摩擦比。