輥简单机械[知识回顾]一、杠杆及其平衡条件1郾一根硬棒,在力的作用下如果能绕着摇摇,这根硬棒就叫杠杆郾2郾杠杆的五要素:杠杆绕着摇摇摇摇叫支点;使杠杆转动的力叫动力;摇杠杆转动的力叫阻力;从到摇摇的距离叫动力臂;从到的距离叫阻力臂郾3郾研究杠杆的平衡条件,需要的实验器 Roller simple machinery [knowledge review] 1. Lever and its balancing conditions 1 郾 a hard rod, if it can be shaken around under the force of the force, this hard bar is called lever 郾 2 五 lever of the five elements: Lever winding Shake and shake the fulcrum; the force that turns the lever calls power; the force that rotates the lever is called resistance; the distance from where it shakes is called the power arm; the distance from where it comes is called the resistance arm 郾 3 郾 study the balance condition of the lever, Needed experimenter