·知识体系及复习要求·简单机械和功杠杆力臂的概念 (理解 )画杠杆的力臂 (会 )杠杆的平衡条件Ｆ1ｌ1=Ｆ2 ｌ2 (理解 )滑轮定、动滑轮的作用和特点 (知道 )滑轮组的作用和特点 (知道 )组装滑轮组 (会 )功做功的两个必要因素 (理解 )功的计算公式 (理解 )功的单位 (知道 )功的 ·Knowledge system and review requirements ·The concept of simple mechanical and power lever arm (Understand) The balance condition of the lever (will) lever of the drawing lever F1l1=F2 l2 (Understand) The function and characteristics of the pulley fixed and moving pulley (know) The pulley set The role and characteristics (know) of the two necessary factors for the assembly of the pulley (will) work (comprehension) the formula for the work (understand) the unit of work (know) work