Warning: file_put_contents(/www/wwwroot/ppbbbu/n94.cn/cache/cb4087aa3714eb12630f672756daae77.txt): failed to open stream: No space left on device in /www/wwwroot/ppbbbu/n94.cn/index.php on line 55 coefficient of friction英英字典_coefficient of friction剑桥英语解释_coefficient of friction柯林斯英文解释_94生活常识网有道词典
1. N the force required to move two sliding surfaces over each other, divided by the force holding them together. It is reduced once the motion has started 摩擦系數[mechanical engineering]