“杠杆的平衡条件”一节安排有学生探究杠杆的平衡条件的分组实验。该实验设计要求调节杠杆两端的平衡螺母,使杠杆在不挂钩码时保持水平并静止,达到平衡状态。若给杠杆两端挂上不同数量的钩码,移动钩码的位置,使杠杆重新水平平衡;然后在杠杆的刻度上读出动力臂、阻力臂,再根据钩码的个数算出动力和阻力,找出它们之间的关系,得出杠杆的平 “Lever of balance conditions ” section arranged students to explore the equilibrium conditions of the grouping experiment. The experimental design requires that the balance nut be adjusted at both ends of the lever to keep the lever horizontal and stationary while not hooking the code to reach a balanced condition. If the hook ends hung a different number of hook code, move the hook code position, so that the lever again horizontal balance; and then read the lever on the scale arm, resistance arm, and then according to the number of hook code to calculate the power and resistance , Find out the relationship between them, draw the lever of peace