Study On The Level Of Conceptual Understanding Of "Momentum And Its Conservation Law" In High School Physics Based On Mental Model Constraction

Based on the Mental Model Construction theory,this paper aims to define the three levels of students' understanding of physical concepts from the perspective of Mental Model Construction.And take the high school physics "momentum and its conservation law" as the carrier,specifically study the students' understanding level of "momentum and its conservation law" related concepts.First of all,on the theoretical level: Firstly,the importance of the conceptual understanding of "momentum and its conservation law" is analyzed,and the research related to "momentum and its conservation law" is collected.It is found that students have difficulties in understanding the concept of momentum,and many students do not have a deep understanding of the relevant concepts,therefore,this paper emphasizes the importance and necessity of understanding physical concepts based on Mental Model Construction.Secondly,this paper summarizes the connotation and formation mechanism of Mental Model,and summarizes the process of conceptual understanding based on Mental Model Construction.On this basis,three levels of physical conceptual understanding are defined.Thirdly,based on the concepts related to "momentum and its conservation law" in high school physics,this paper defines the three levels of the conceptual understanding of "momentum and its conservation law" by collecting the misconcepts related to momentum and matching them with the level of concept understanding.Secondly,the project design and questionnaire design are carried out according to the misconcepts at each level of the conceptual understanding of "momentum and its conservation law".After the face validity and expert validity of the questionnaire were tested,106 seniorhigh school students who have completed the "momentum and its conservation law" were selected for pretest.After using the RASCH model for data processing,it was found that there were two questions that did not match the level of division.So,after modifying the two test questions,145 high school students were re-selected for the post-test.Each item in the final questionnaire is at the corresponding level and conforms to the RASCH model.Finally,through the analysis of the data,the rationality of the definition of "momentum and its conservation law" conceptual understanding level and the rationality of the definition of physical concept understanding level are verified.That is,the level of understanding of physical concepts can be divided into:Level one: Be able to identify physical phenomena,remember definitions and formulas and apply them directly,but can't establish the relationship between physical phenomena and mathematical formulas,only master physical theory from the level of proposition representation.Level two: Be able to explain and predict physical phenomena,and be able to abstract physical models from physical phenomena with the help of mathematical models(that is,be able to describe physical phenomena with mathematical models and understand the physical meaning behind the mathematical models),so as to establish the relationship between physical phenomena and physical theories.Be able to understand physical theory from the semantic content and syntactic structure of physical theory.Level three: Be able to explain and predict physical phenomena,and can abstract physical models from physical phenomena without mathematical models,so as to establish the semantic relationship between physical phenomena and physical theories,and truly understand physical theories.As for the students' understanding of the concept of momentum,the contents of each level are as follows:Level one: Be able to identify physical phenomena related to momentum conservation,master concepts and formulas of momentum,impulse,momentum theorem and momentum conservation based on memory level,and apply them directly.Level two: Be able to analyze physical phenomena based on mathematical formulas(momentum theorem formula,momentum conservation formula),so as to establish the relationship between physical phenomena and physical theory.Level three: Be able to explain and predict physical phenomena with the help of the semantic content of momentum theorem and momentum conservation,independent of mathematical expression.In summary,the level of understanding of the three physical concepts defined in this paper can be applied not only to "momentum and its conservation law",but also to other chapters of physics,which also provides the basis and direction for subsequent research.