The Treatment of the Laws of Dynamics in Higher Level Schools

Summaries

English

This paper describes how the three Newtonian laws of dynamics are introduced in the higher grades of secondary schools in the Soviet Union. Particular attention is given to the treatment of the second Newtonian law.

The authors reject the widely used method of introducing this law as an equation defining mass from which it is presented as a constant of proportionality between a statically measured force and acceleration.

As an alternative, a method is described showing how the concept of mass can be introduced independently of the second Newtonian law. The accelerations resulting from the interaction of two bodies are considered as being a property of the bodies (inertia)‐‐quantified in the concept of mass. The second Newtonian law follows from experiments showing that for bodies of different masses submitted to the same force the products of their masses by their accelerations (ma) are equal and may serve as the measure of the force.     

经典力学的剖析与发展

论证了惯性质量，引力质量，惯性参照系，惯性力的不合理必，确定了物质质量的概念，统一了惯性参数照系和非惯性参照系，否定了力的绝对性，引出了加速相对性原理和力相对性原理，提出了相对力，相对加速度，相对参照系和绝对力，绝对加速度，绝对参照系的新概念，建立起初步绝对相对论力学。     

对惯性定律教学内容的调查研究

惯性定律是力学以及整个物理学理论体系的逻辑起点,是大学物理的经典内容。研究表明,国内目前在涉及惯性定律内容的教材编写和教学内容的组织中存在问题,物理学教材编写时应树立大知识观或科学观的理念,应充分考虑物理学理论的整体结构,既要求每个层次的陈述内部在逻辑上自洽,也要求不同层次的陈述之间相互协调;在教学内容组织和惯性、惯性定律的建构时应该采用历史方法和逻辑方法,保持历史方法和逻辑方法的张力。     

The Law of Inertia: How Understanding its History can Improve Physics Teaching

The law of inertia is a problem in teaching due to the impossibility of showing the proposition experimentally. As we cannot do an experiment to verify the law, we cannot know if it is correct. On the other hand, we know that the science based upon it is successful. A study in the history of mechanics has shown that there are different foundations for the law but also that the law plays the same role in the science since Newton. To avoid a statement of which we cannot be sure, the present paper proposes to understand the law through its function in the theory. In this case, we do not have to say how a free body moves, but rather that the rectilinear and uniform motion is the motion of reference in Newtonian mechanics.     

Newton's Third Law after Newton

Newton's third law is not something which students easily accept. This is largely due to the widespread notion that the force exerted by a moving body is directly related to the speed or to the mass of the body (or to both) and not to the nature of any interaction in which that body might be involved. The aim of the paper is to identify some of the issues upon which debate took place over the phenomenon of impact in the early 18th Century. This is achieved by studying a number of the popular textbooks and commentaries on mechanics which were published at that time. Some implications for teaching Newtonian mechanics are outlined. Specializations: physics education, concept development, history and philosophy of science in science teaching.     

Simulation-based performance assessment: an innovative approach to exploring understanding of physical science concepts

This paper illustrates the use of simulation-based performance assessment (PA) methodology in a recent study of eighth-grade students’ understanding of physical science concepts. A set of four simulation-based PA tasks were iteratively developed to assess student understanding of an array of physical science concepts, including net force, acceleration, velocity, and inertia. Illustrative examples drawn from the administration of these simulation-based PA tasks to a sample of eighth-grade students (n?=?74) highlight the potential of simulation-based tasks for revealing conceptual understanding of science concepts and for informing curriculum development within the context of design-based implementation research. The paper also describes a variety of challenges encountered over the course of the development, administration, and analysis of the PA data that may be informative for researchers and educators as they consider implementing simulation-based PAs.     

Bridging History of the Concept of Function with Learning of Mathematics: Students’ Meta-Discursive Rules,Concept Formation and Historical Awareness

In this paper we present a matrix-organised implementation of an experimental course in the history of the concept of a function. The course was implemented in a Danish high school. One of the aims was to bridge history of mathematics with the teaching and learning of mathematics. The course was designed using the theoretical frameworks of a multiple perspective approach to history, Sfard’s theory of thinking as communicating, and theories from mathematics education about concept image, concept definition and concept formation. It will be explained how history and extracts of original sources by Euler from 1748 and Dirichlet from 1837 were used to (1) reveal students’ meta-discursive rules in mathematics and make them objects of students’ reflections, (2) support students’ learning of the concept of a function, and (3) develop students’ historical awareness. The results show that it is possible to diagnose (some) of students’ meta-discursive rules, that some of the students acted according to meta-discursive rules that coincide with Euler’s from the 1700s, and that reading a part of a text by Dirichlet from 1837 created obstacles for the students that can be referenced to differences in meta-discursive rules. The experiment revealed that many of the students have a concept image that was in accordance with Euler’s rather than with our modern concept definition and that they have process oriented thinking about functions. The students’ historical awareness was developed through the course with respect to actors’ influence on the formation of mathematical concepts and the notions of internal and external driving forces in the historical development of mathematics.     

牛顿第二定律对变质量问题的应用

从经典力学范围和相对论力学两方面,分别讨论了牛顿第二定律的应用条件,并从所导出的牛顿第二定律解决变质量问题的公式,通过具体举例说明了如何应用变质量公式来解决实际问题.     

土力学课程讲授中的学生人文素质培养浅析

土力学是土木工程等专业所开设的一门专业基础课。结合专业课程的讲授,加强理工科学生的人文素质教育,有助于培养出具有健全的理想人格、崇高的精神境界、辩证的思维模式的理想人才。文章选取土力学的发展历史、土的三相物理性质指标和基底压力的分布规律等三个知识点,具体阐述了在土力学课程教学过程中如何加强学生的人文素质培养的一些探索与实践。     

恩格斯的历史合力论及其当代意义

恩格斯的历史力论从历史是人们自己创造的这一前提出发,围绕历史发展中的个人意志和客观规律的关系,深刻揭示了历史发展是合目的性和合规律性的,充分肯定了个人的意志和活动在历史发展中的作用,指明了社会规律和自然规律的区别和联系以及历史发展是一个曲折复杂的过程。这一理论在当前对于我们如何准确把握“生产力标准”,认识和发挥第五个社会成员的价值和作用,把握世界历史的进程和发展趋势,全面推进我国社会的进步和发展具有重要的指导意义。     

A Study on Student Teachers’ Misconceptions and Scientifically Acceptable Conceptions About Mass and Gravity

The aims of this study were considered under three headings. The first was to elicit misconception that science and physics student teachers (pre-service teachers) had about the terms, ‘‘inertial mass’’, ‘‘gravitational mass’’, ‘‘gravity’’, ‘‘gravitational force’’ and “weight”. The second was to understand how prior learning affected their misconceptions, and whether teachers’ misconceptions affected their students’ learning. The third was to determine the differences between science and physics student teachers’ understanding levels related to mass and gravity, and between their logical thinking ability levels and their attitudes toward physics lessons. A total of 267 science and physics student teachers participated in the study. Data collection instruments included the physics concept test, the logical thinking ability test and physics attitude scale. All instruments were administered to the participants at the end of the 3rd semester of their university years. The physics test consisting of paper and pencil test involving 16 questions was designed, but only four questions were related to mass and gravity; the second test consisted of 10 questions with two stages. The third test however, consisted of 15 likert type items. As a result of the analysis undertaken, it was found that student teachers had serious misconceptions about inertia, gravity, gravitational acceleration, gravitational force and weight concepts. The results also revealed that student teachers generally had positive attitudes toward physics lessons, and their logical thinking level was fairly good.     

电路课程教学设计

教学设计是教学过程中的重要环节,文章介绍了笔者在电路理论课程中应用对偶原理提高授课效率和改善授课效果的一些做法及体会。实践结果证明：此设计方法是可行的,对偶的概念是求解电路问题的一个省时而有效的方法。有助于学生理解和掌握电路基本概念和基本分析方法,提高了授课效率。     

用阿德伍德机验证牛顿第二定律

本文给出了用阿德伍德机验证牛顿第二定律的实验原理和实验装置,介绍了用阿德伍德机的实验方法验证在总质量m不变的情况下,合外力f与加速度a的关系;在合外力f不变的情况下,1/m与a的关系。同时,给出了用阿德伍德机验证牛顿第二定律的实验结果,结果表明该方法简单可行和有一定的精度,我们在教学中使用效果较好。     

能量守恒科学

在能量守恒科学中,占统治与主导地位的是能量守恒定律.其他的定律,或者可由能量守恒定律导出,或者必须经受能量守恒定律的检验,或者是错误的.主要讨论四个问题:根据能量守恒定律重新考虑力与质量、速度的关系;重新导出其他定律,如万有引力定律、库仑定律等;检验其他定律是否可以应用,给出动量守恒定律和动量矩守恒定律不成立(其结果与能量守恒定律相矛盾)的实例;将旧的学科改造成为新的学科,例如将牛顿力学改造为新牛顿力学.新牛顿力学可以部分取代相对论并解决相对论无法解决的问题.     

高职院校法律基础课教学中存在的问题及对策研究

高职院校“法律基础”课承担着向学生传授法律基础知识、增强学生法律意识和提高法律素质的重要任务,课堂教学是实现这一目标的主渠道。而在教学实践中却存在对法律基础知识重视不够、对法律意识提升不够以及现代法治观念彰显不足等问题和偏差,没有把法律教育目标最终落实在提高学生法律素养这一层面。本文以法律基础教育目标的三个层次为参考,分析了法律基础教学中存在的问题,提出了改进法律基础课教学要遵循法律教育目标的“三层次”、突出学生主体地位、整合资源,寻求多种途径提高教师素质,鼓励学生参加各种法律社会实践。     

Mechanics as the Logical Point of Entry for the Enculturation into Scientific Thinking

Force in modern classical mechanics is unique, both in terms of its logical character and the conceptual difficulties it causes. Force is well defined by a set of axioms that not only structures mechanics but science in general. Force is also the dominant theme in the ‘misconceptions’ literature and many philosophers and physicists alike have expressed puzzlement as to its nature. The central point of this article is that if we taught mechanics as the forum to discuss the nature of mechanics itself, then we would serve to better secure a learner’s understanding and appreciation of both science and mathematics. We will attempt to show that mechanics can provide the opportunity for students to enter this meta-discourse by engaging in Socratic discussion, entertaining thought experiments, comparisons made between force as defined within mechanics as a modern axiomatic system with Newton’s quantitative definition of force, how the concepts of force prior to Galileo and Newton can be used as a teaching aid with respect to student intuitive ideas and how mathematics was brought to bear on what is given empirically. Mechanics provides this opportunity and pedagogically may require it due to its axiomatic nature.     

中学生牛顿力学部分概念相异构想的调查研究

牛顿力学在中学物理中占有重要的地位,学生对这部分概念的理解和掌握,影响到力学其他部分知识及后续课程的学习.采用分层随机抽样方法,对山东省平邑一中的136名学生进行了牛顿力学概念相异构想的调查统计.分析了学生存在的相异构想、相异构想的特点和成因,并且提出了转变相异构想的教学策略,为中学物理教学提供了有益的启示.     

力学规律的结构研究

在普通物理学的力学部分 ,几个常用的定律和定理是 :牛顿定律、动量定理、动量守恒定律、功能原理、机械能守恒定律等 .它们反映了物体运动所遵循的基本规律 ,是解决力学问题的钥匙和原则 .其中最基本的或者最重要的是牛顿第二定律 ,其余各定律或定理都可以通过适当的转换而推导出来 .本文通过对牛顿第二定律的研究 ,找出力学基本规律的内在结构关系及各自成立的条件 ,从而有利于正确灵活使用各定律、定理解决有关物理问题     

工程力学“金课”建设研究及教学实践

工程力学是高等院校工科类学生的专业基础课程,旨在培养学生的力学素质,加强学生对工程概念的理解,为以后的专业课学习打好理论基础,在工科学生整个本科阶段的教学过程中起到承上启下的作用。针对目前工程力学"金课"建设中需要注意的问题,结合多年的教学经验进行了探讨,提出工程力学"金课"建设教学设计和具体措施。     

电机实践课程的改革与创新

“电机学”是电气工程专业一门重要的专业技术基础课程,是一门教师难教、学生难学的课程,其理论性强、抽象概念多、涉及的基础理论知识广;因此,研究如何通过丰富实践教学环节来加深学生对课程的理解变得尤为重要。为丰富电机实践课程教学环节,弥补以往该课程实践教学环节存在的诸多问题,对当前实践教学现状及存在的问题进行了分析,从丰富完善教学内容、设计电机拆装与维修实训软件、探索与分析电机实践课程教学规律、“电机实验与实践”课程教材建设等方面提出了具体的改革举措。