A Probe Into The Teaching Of Physics Buoyancy In Junior Middle School

Buoyancy is one of the basic knowledge with strong application in hydrostatics,and it is also an important content of physics teaching in junior middle school.The chapter "buoyancy" in junior middle school is based on the cause of buoyancy,Archimedes principle is the core,the buoyancy condition and the application of buoyancy are the forms of expression.In the teaching of problems,buoyancy is more comprehensive and involves more knowledge points.It requires not only the composition of the students undefined grip force,the balance condition of the force,the pressure,the liquid pressure,the density,the relationship between movement and force,and so on.Moreover,students are required to have a certain ability of derivation and spatial imagination,which is a difficult point and a key point in the teaching of junior high school problems.In recent years,the teaching of physics buoyancy in junior high school has been paid attention to by physics educators,and a lot of research has been done,but it is rather scattered.On the basis of previous research,this subject makes a systematic inquiry.The specific work is as follows: firstly,the students of Grade 8 in three junior middle schools in Chongqing are investigated.Through setting up the basic buoyancy problem to investigate the current situation of the students in solving the problem.It is found that most students do not have a deep understanding of the relationship between the density of liquid and the buoyancy.It needs to be further improved when the state of the object in the liquid is used to analyze the force condition.Secondly,under the guidance of Piaget undefineds cognitive development theory and Yekisdorson undefineds law,combined with the communication with junior middle school physics teachers and practical teaching experience,this paper analyzes the characteristics of the present situation of junior middle school students undefined buoyancy problem.It is found that the students undefined ability to solve buoyancy problems independently and the ability to simplify physical models are weak,and the computational ability needs to be improved when using mathematical methods to solve problems.Thirdly,by analyzing a large number of buoyancy exercises and taking the knowledge points involved in theexercises as clues,this paper classifies the buoyancy problems of junior middle school physics.It is found that the topic involves a wide range of knowledge,and the form of proposition is usually the parallel setting of knowledge points such as pressure,density,buoyancy and so on.Fourthly,using the method of literature research and case analysis,the basic methods to solve the buoyancy problem are sorted out,which are pressure difference method,weight indicating method,balance method and Archimedes principle.Fifthly,using qualitative analysis method and case analysis method,it is found that the most abstract problem is liquid level change type,so we use pictures to depict the appropriate physical situation and classify the difficult and heavy problem type-the liquid level change type.The methods to solve the problem of liquid level change are listed in turn,which are integer method,commutation method,comparison method,liquid jelly method,inference method and constant value method.Through the teaching inquiry of physics buoyancy in junior middle school,especially the detailed analysis of the problem of changing liquid level,it is believed that this paper can help to train students to analyze the problem of buoyancy and the teaching of buoyancy.