The first part: The model essay "Synthesis of Force" selected from the template of physics teaching plan for senior three is the content of the tenth section of Chapter 5 "Force and Balance" of xx compulsory X, and it is one of the key contents of this chapter; Mechanics is the foundation of high school physics, so the content teaching in this chapter is related to the success or failure of high school physics teaching, so the teaching in this chapter is particularly important. Based on the preliminary concepts of learning force and common force, this section studies the resultant force of various forces, which has the following characteristics:
1. I learned the balance of two forces as the basis in junior high school;
2. Students already know scalars and vectors;
I learned the diagram of force in the course of gravitation.
Therefore, the main teaching contents of this section are: the synthesis of resultant force, component force, * * point force and * * point force, and the relationship between the magnitude of resultant force F and the included angle α of component F 1, F2. Combining the content and characteristics of the teaching materials, aiming at improving the scientific literacy of all students, we should train students from the "three-dimensional goal" of the new curriculum. According to the requirements of the syllabus and the new curriculum standards, the following teaching objectives are put forward:
Knowledge and skills:
1. The concepts of synthesis and resultant force can be understood from the function of force.
2. The parallelogram rule is a general rule of vector operation. You can distinguish between vectors and scalars through experiments and master the magnitude of force.
3. It will be used as a graphic method to find the resultant force of * * * point forces, and it will calculate the resultant force of several * * * point forces on the same line.
4. Knowing the relationship between the resultant force of two * * * point forces and the included angle, we use the knowledge of right triangle to calculate the resultant force of * * * point forces.
Process and method
Learn to design experiments and observe experimental phenomena; And the research methods of induction and summary.
Emotional attitudes and values
Learn to use the equivalent physics thought to solve problems, and cultivate students' scientific attitude of seeking truth from facts.
Senior one students' thinking is single and fixed, changing from perceptual knowledge to rational knowledge. The focus of this section is to illustrate the concepts of synthesis and resultant force through examples. The difficulty in teaching is to understand the parallelogram rule.
Theory and teaching method
Physics teaching focuses on inspiring thinking and teaching methods. Students have their own understanding of the balance of two forces, which can be used as the starting point of teaching. Under the guidance of the teacher, let the students analyze what is * * * point force, sum up the difference between resultant force and component force, explore the parallelogram rule of force synthesis through experiments, and further connect with life, and expand to the synthesis of multiple * * * point forces; Make students fully understand the textbook and grasp the important and difficult points; Therefore, this course comprehensively uses intuitive teaching method, inductive summary method and experimental inquiry method combined with multimedia means. In teaching, we should strengthen the two-way activities between teachers and students, ask questions and evaluate them reasonably, and guide students to actively explore new knowledge.
Methods of speaking and learning
Students are the main body of classroom teaching, and modern education takes students as the center, paying more attention to the guidance of students' learning methods in the teaching process and guiding students to actively explore new knowledge. In the teaching process of this class, on the basis of junior high school, review the balance of two forces, guide students to learn the concept of resultant force, and emphasize that the synthesis of forces is not simple algebraic addition and subtraction; Then let the students explore what kind of law the synthesis of force satisfies. Guide students to actively think and explore parallelogram rules; Observe and summarize. Clever use of questioning and evaluation can activate students' enthusiasm, mobilize the classroom atmosphere, and enable students to complete their learning tasks in a relaxed, independent and discussed learning environment.
On the Teaching Process
From the above analysis, it can be seen that mastering knowledge in teaching is the center and cultivating ability is the direction; Grasp the key points and break through the difficulties. Design the following teaching procedures:
1. Import a new lesson: (It takes about 5 minutes)
Projection (showing the beauty of balance in nature) makes students realize that the phenomenon of force and balance can be seen everywhere, thus stimulating students' curiosity and thirst for knowledge. Bring students' thinking into the classroom.
2. New course teaching: (about 35 minutes)
Ask questions (what is * * * power) and let the students read the textbook and answer the questions. The teacher explained the concept of * * * point force with examples, emphasizing that the extension lines of several forces will intersect at one point, which is * * * point force.
Teachers review the knowledge of "the balance of two forces" in junior high school, so that students can review the synthesis of two forces on the same line; Basic concepts of component and resultant force. The teacher gave an example (painting on the wall, one person carrying a bucket of water, two people carrying a bucket of water together and so on). ) and made a force analysis diagram, pointing out that the forces are not in the same straight line. How to synthesize power? Students think and discuss. Teachers provide students with rubber bands, dynamometer, ruler, blank paper, etc. Let the students read 82 pages of experimental inquiry and conduct experiments in groups. Teachers guide students to experiment, summarize and summarize. Then the parallelogram rule is obtained. In the inquiry experiment, the teacher explained the difference between component force and resultant force, and the difference between resultant force and force synthesis. Students can experience the relationship between the resultant force and the original two forces and the included angle through hands-on experiments, so as to better grasp the calculation law of vectors different from scalars.
Teacher's example (horizontal right force f1= 45n; Vertical upward force F2; Let the students analyze and answer the problem-solving ideas, and the teacher will further expand to the synthesis of multiple points. This is from simple to complex, which accords with students' cognitive characteristics. The teacher summarizes the contents of this section, and then explains and consolidates the examples to stabilize the students' knowledge. Finally, assign homework. (On the blackboard: In teaching, half of the blackboard is used to write concepts, and the other half is used to draw and analyze. )
Conclusion: In the above design, I strive to be "student-centered" and actively advocate students' thinking, autonomous learning and active inquiry based on physical experiments. At the same time, we should adjust the teaching according to the needs of students and the actual situation in the classroom, and constantly reflect and summarize. Here, teachers and leaders are also invited to criticize and correct me. Thank you.
The second part: the analysis of model essay teaching in physics teaching plan of senior three.
Electromotive force is the difficulty of this chapter. The textbook clearly puts forward the concept of "non-electrostatic force", so that students can understand non-electrostatic force from the perspective of work and energy, understand the role of non-electrostatic force in circuits, and understand the concept of electromotive force from the perspective of "non-electrostatic force" doing work.
At the same time, in order to reduce the difficulty, the textbook directly gives the definition of electromotive force, but it only says that electromotive force is equal to the work done by non-electrostatic force to transfer the positive charge of 1C from the negative electrode to the positive electrode in the power supply, and it is not strictly defined by the ratio method. The internal resistance of power supply is very important in the study of ohm's law of closed circuit. This section has made some preparations.
We often say that students should go through the scientific process in various forms. Students understand new laws through discussion or experiment, understand the work process of predecessors through reading, and accept new concepts with teachers' ideas, all of which are different forms of experiencing the scientific process.
Teaching objectives
1. You should know that the power supply is a device that converts other forms of energy into electrical energy.
2. Understand the relationship between electrostatic and non-electrostatic work and energy conversion during the directional motion of free charge in the circuit (outside and inside the power supply).
3. Understand the basic meaning and definition of electromotive force of power supply.
4. Understand the internal resistance of power supply.
Emphasis and difficulty in teaching
The establishment of the concept of electromotive force is both important and difficult. This set of books expounds and paves the way for the idea of "learning energy by doing work" in many places. Here we use this functional relationship to learn electromotive force. It can make students have a deep understanding of the electromotive force of power supply and cultivate students' rational thinking habits. In this lesson, the concept of electromotive force is established by comparing electrostatic work with non-electrostatic work. It also paves the way for studying ohm's law of closed circuit in section 7.
Teaching methods and means
Experimental demonstration and logical reasoning. In the two confusing concepts of voltage and electromotive force, electrostatic force and non-electrostatic force are used for comparative teaching to establish a new concept.
Preparation before class
Teaching media.
Metal plate, acid solution, sensitive galvanometer, all kinds of dry batteries, student power supply, wires, keys, small bulbs, projectors.
Knowledge preparation
1. Review before class: Definition of potential difference: U=Wq.
2. Explain before class: In a metal conductor, the charge that can move freely is a free electron. Because of the negative charge, the directional movement of electrons in one direction is equivalent to the directional movement of positive charges in the opposite direction. For the sake of discussion in this section, the positive charge is shifted.
Chapter three: Select the model essay knowledge target of physics teaching plan template in senior three.
1, know how the eddy current is generated;
2. Know the disadvantages and benefits of eddy current, and how to prevent and use it.
Affective goal
Through the analysis of examples, cultivate students' comprehensive understanding and scientific attitude towards things.
Teaching suggestion
This course is an elective course, which is a special electromagnetic induction phenomenon and has many applications in practice, such as generators, motors, transformers and so on. Therefore, it is the key content of this lesson to choose a lecture according to the actual situation, or to understand what eddy current is and let students read it.
Eddy current, like self-perception, has both advantages and disadvantages. We should make full use of these examples in teaching to cultivate students' scientific attitude towards things in an all-round way.
Teaching design scheme
Introduction: Guide students to observe generators, motors and transformers (in kind or in pictures).
Question: Why is their iron core not a whole piece of metal, but made of many thin silicon steel sheets insulated from each other?
Guide the students to read and answer, thus leading to the concept of eddy current: what is eddy current?
When a piece of metal is placed in a changing magnetic field or moves in a magnetic field, it will generate induced current in the metal block and form a closed loop in the metal block, much like a vortex of water, so it is called eddy current. The resistance of the whole metal is very small, so the eddy current is often very large.
Let the students understand that eddy current is the electromagnetic induction phenomenon of the whole conductor and obeys the law of electromagnetic induction.
Second, what is the practical significance of eddy current?
(1) Why are motors and transformers generally made of thin silicon steel sheets and insulated from each other, so as to reduce the loss caused by eddy currents?
⑵ What are the advantages of high-frequency induction furnace smelting metal?
How to use eddy current principle for electric measuring instruments to facilitate observation?
After asking the above questions, let the students read, discuss and answer.
Third, homework
Ask the students to go to the physics laboratory in their spare time to observe how the watt-hour meter uses eddy current and write a short article to explain it.
The fourth part: the selection of physics teaching plan template for senior three. First, the analysis of teaching content
In the process of reviewing this chapter, we should pay attention to the difference between definition and judgment; Understanding and application of basic concepts and laws, such as correctly distinguishing the relationship between various powers (electric power, thermal power, mechanical power, etc.). ), calculation formula, and the difference between pure resistance circuit and impure resistance circuit; The assessment in this chapter is mostly in the form of multiple-choice questions and experimental questions, especially the experimental assessment is flexible, including instrument selection, reading, equipment connection, data processing, error analysis and so on. Therefore, the review of experiments in electricity should focus on the selection of two methods for measuring resistance by voltammetry, the selection of voltage-dividing connection and current-limiting connection of sliding rheostat and the analysis of circuit faults, so as to deepen and consolidate the understanding of basic knowledge and cultivate students' ability to solve problems.
Second, the analysis of learning situation
Students have mastered the contents of this chapter through the study of the new curriculum, but their understanding and application ability of basic concepts and laws are still weak, and they are weak in the selection of equipment and sliding rheostat in experimental questions and the analysis of circuit faults. Therefore, when reviewing, we should strengthen our ability to understand and apply the basic laws, especially the review of the experimental part.
Third, the teaching objectives:
(A) knowledge objectives
1. Familiar with and able to use the law of resistance and the rules of series-parallel circuit.
2. Know the electromotive force and internal resistance of power supply, and know the Ohm's law of closed circuit.
3. Master the difference and calculation of electric power, thermal power and mechanical power; Joule's law and its application.
4. The principles, operation steps, equipment selection and connection selection of the four experiments in this chapter; Circuit fault analysis.
(Electrical experiments will be reviewed separately)
(2) Process and method
1, list important knowledge points.
2. Use learning plans to guide learning, and combine explanation with practice.
Emotional attitudes and values
1. By explaining the operation rules, matters needing attention and data analysis of each experiment, students can appreciate the rigor of the experiment and cultivate the scientific spirit of earnest inquiry and seeking truth from facts.
2. Through the analysis of circuit faults, the calculation and analysis of typical circuit calculation problems and the corresponding experiments, students can realize the practicality of circuit rules and the sense of achievement in solving practical problems by using the learned rules, thus deepening their interest in the subject.
Four, the teaching emphasis and difficulty:
1) understand ohm's law of closed circuits.
2) Difference and calculation of electric power, thermal power and mechanical power.
3) The principles, operation steps, equipment selection and connection selection of the four experiments in this chapter; Circuit fault analysis.
Five, teaching strategies:
Establish a block diagram of important knowledge points, and strive to be concise; Reviewing the experiments in electricity, we should pay attention to the selection of two methods for measuring resistance by voltammetry, the selection of voltage-dividing connection and current-limiting connection of sliding rheostat, and the analysis of circuit faults. Use the study plan to guide the study, and pay attention to the combination of speaking and practicing in the review.
Chapter 5: Choose the model essay 1 of physics teaching plan for senior three, understand the concepts of amplitude, period and frequency, and know the meaning of total vibration.
2. Understand the concepts of initial phase and phase difference, and understand the physical meaning of phase.
3. Understand the physical meaning of each quantity in the displacement equation of simple harmonic vibration, and describe the vibration image according to the vibration equation.
4. Understand the physical meaning of simple harmonic vibration images, and judge the amplitude, period and frequency according to the vibration images.
Emphasis and difficulty: understand the concepts of amplitude, period, frequency and total vibration of simple harmonic vibration, and the physical meaning of phase.
Teaching suggestion: Take the spring vibrator as an example. When observing the periodicity of displacement change and the characteristics of vibration speed, the physical quantities (amplitude, period and frequency) describing simple harmonic vibration are introduced, and then the concept of phase is introduced through simple pendulum experiment. Finally, the images obtained in the last section are compared with mathematical expressions to further understand the meaning of these physical quantities. Please pay special attention to the concept of phase in this section.
Introduce a new lesson: Do you have a favorite singer? We often evaluate when listening to songs. Singer Han Hong has a wide range and a bright and mellow tone. Singer Cyndi Wang has a sweet voice; Singer Chris Lee's voice is hoarse and unique ... but the same song, sung by most ordinary people, often seems dry and monotonous. Why? These are all determined by timbre, which is related to frequency and so on.