Reflection on the research of leverage

Part 1: Reflection on the Teaching of Leverage

This lesson is based on the study of the lever rule in the previous lesson to find out how the levers are labor-saving, labor-intensive, effortless, and effortless. For this lesson teaching, simple and boring preaching can't make much effect. It is necessary to pass through the physical objects as much as possible, to stimulate the interest of learning through the hands-on operation of students, to understand the mystery of science in the game, and to master the corresponding scientific knowledge.
The first part of the textbook is how to distinguish between levers is labor-saving, laborious, effortless and effortless. I told students that they can be divided into two steps. 1. First, find the pivot point, force point and resistance point of the lever tool; 2. Analyze three points. The positional relationship between the two is based on the conclusion of the lever rule experiment. For the iron piece to open the iron bucket cover, the clip clip things, the bottle opener open the beer bottle three activities, let the students analyze in the activity, the first two are easier to master, some students can not find when opening the bottle cap Resistance points and pivots, where teachers are required to guide analysis.
The second part is the analysis of more leveraged tools in life. The teacher should prepare more physical objects. Through the demonstration operation, the students can see the working process of various lever tools. The students can easily find three points. A convenient distinction is what kind of leverage is applied. For scissors, it is necessary for the teacher to supplement. For the same pair of scissors, the method of use is different, and the labor saving or laborious situation is different. For the two lever-type tools of laborious scorpion and chopsticks, guide students to think "Why should it be designed to be laborious?

Part 2: Reflection on the research of leverage

Under what circumstances, leverage is labor-saving? Under what circumstances is leverage difficult? Under what circumstances is leverage not laborious or effortless?
The key to answering these three questions is the comparison of the force point to the fulcrum distance and the resistance point to the fulcrum distance. How can students find the relationship between the two?
In the classroom teaching, I first work with the students to confirm what is labor-saving?
"When the force point is two hook codes and the resistance point is a hook code, is the lever level, is it labor-saving or laborious?"
"Strong"
"When the force point is a hook code and the resistance point is two hook codes, is the lever level, is it labor-saving or laborious?"
"saving effort"
When the labor-saving and laborious standards are determined, I will pass several sets of data to the students, let them judge whether they are labor-saving levers or laborious levers.
Students quickly judge after passing the self-action verification
At this point, I asked for the first time, "From our data table, we can find out when is leverage saving?"
At this time, there are not many students who can express their opinions. However, some students have vaguely guessed the relationship between labor saving and distance, and they can never get rid of the interference of the number of hooks.
In order to help the students understand, I erased all the hook codes in the form from the blackboard, leaving only the number of grids and verification information.
The students’ eyes were bright, the main information that interfered with them was gone, and the close relationship between distance and three kinds of leverage was quickly discovered.
In order to consolidate the students' findings, I will present several sets of data again, let the students judge first, and then use the lever rule to verify. In this process, the students once again experience three kinds of levers and force points to the fulcrum distance and the resistance point to the fulcrum distance. Relationship.

Part Three: Reflection on the Teaching of Leverage

In this lesson, I chose the lever rule as the research material. I used the activity method in the textbook to let the students experience the debugging activities of the lever rule under different conditions. Through observation, record, and analysis of the experimental data, the law of lever effort was found. Through these activities, students are guided to analyze the leverage tools we have used, and students are required to draw work charts to consolidate the understanding of this method. The difficulty in teaching this lesson is the ability to analyze and sort out the rules of leverage and effort from the many seemingly messy data. It can be said that the inquiry activity is successful, but there are still some students who do not fully understand and analyze this lesson. I think it is my own complicated teaching materials. In fact, I did not emphasize the key points and strengths in this lesson. The students imposed the key points and strengths on the students without any basic conditions, which made them more difficult for the students, which affected the understanding of some students.