教学《轮轴》一课时,学生利用机械实验盒中提供的材料自行研究,可以发现轮轴“在轮上用力时省力,在轴上用力时费力”这一特点。由于实验材料的局限,对于轮轴的“当轴的大小一样时,轮越大越省力”这个特点却不便于学生去实验发现。为弥补这一学具的缺陷,我发动学生搜集准备百事 Teaching “Axle” Lesson, students use the materials provided in the mechanical experiment box to conduct their own research, you can find the wheel axle “effort on the wheel when the effort, the force on the shaft when hard” feature. Due to the limitation of the experimental materials, it is not convenient for students to experimentally find out that the characteristics of “when the shaft is the same in size and the bigger the wheel is, the more energy-saving” is the wheel shaft. To make up for the shortcomings of this learning tool, I mobilized students to prepare for Pepsi