High school physics three compulsory friction teaching plan

1, knowledge and skills:

Know what friction is; Know which factors are related to the magnitude of friction; Know the advantages and disadvantages of friction.

2. Process and method

Perceive the existence of friction through observation and experiment; Through experiments, the relationship between friction and the pressure on the surface and contact surface of objects is explored, so that students can try to study problems by using scientific research methods such as experiments and induction.

3, emotional attitudes and values:

Through inquiry, let students experience the fun of independent and cooperative inquiry and cultivate their scientific attitude of seeking truth from facts; Through the application of knowledge, students can realize the importance of physical knowledge and its value to society.

Teaching emphasis: apply the method of increasing or decreasing friction to solve practical problems.

Teaching Difficulties: Designing Inquiry Experiments

Learning Style: Exploring Heuristics

Second, teaching preparation.

Student's experimental materials: spring dynamometer, hook block (different from lateral area), hook code, glass plate, towel, several round pencils, etc.

Teaching process:

(A), the creation of situations, the introduction of new courses

I picked up some dirty little glass balls on my way to school, and the teacher washed them with water. Now, please ask two students to take the glass ball out of the container. (Please ask two students to go on stage for 20 seconds to catch the ball, but it is not easy to catch the ball. )

Ask a question: Why is the glass ball not easy to clip? -Students discuss and answer: Too slippery, low friction.

What kind of force do you think friction is? Students describe friction in their own words.

(B), the new lesson learning

1, know what friction is:

What do you know about friction? What else do you want to know? The students answered.

How do you think friction is generated? Let students feel what kind of force friction is, design a simple experiment to feel friction, and understand whether friction helps or hinders the movement of objects.

Students design experiments and practice feelings: students slide their palms on the table and rub their feet back and forth on the floor. And ask the students to answer.

Summary: the phenomenon that our hands and feet are hindered in motion is called friction, and this force that hinders the movement of objects is called friction.

Think about it. What phenomena does friction play in daily life? Which of these frictions are harmful? What are the benefits? Students think and answer.

Obviously, we need to increase beneficial friction,

Teaching design

In order to reduce harmful friction, it is necessary to measure the size of friction and explore ways to change it.

2. Explore what the magnitude of friction is related to:

What do you think friction is related to? Please make a bold guess.

(1) student prediction.

(2) Teacher's nudge: How to measure friction? Please read the content of the textbook, pay attention to pulling the block at a constant speed during the experiment, and think: to prove the relationship between friction and pressure, which conditions should be the same? What conditions can be changed? On second thought, if you need any materials, which are not on the table, the team leader can come to the front to get the materials you need.

(Teachers prompt students to control variables)

(3) Students in each group report the experimental methods to be carried out.

(4) Students should arrange the experimental division of labor in groups.

(5) Students carry out experiments according to the designed methods, and teachers patrol for guidance.

(6) Students feedback the experimental phenomena and explain the reasons.

The teacher summed it up and wrote it on the blackboard.

3. Understand the existence and application of friction, and discuss ways to increase beneficial friction and reduce harmful friction: Where is friction in life? Students discuss, ask and answer.

For example, when people walk, where is the friction? B. imagine: what would it be like to walk without friction? Why are there uneven patterns on the soles?

The car skidded on the ice. What happened to the car? Why? B, how to solve it? (Sprinkle salt, sawdust, cinder, etc.). C. Why are there patterns on the tires?

For example: skiing competition A. Is the friction between the board and the snow harmful or beneficial when skiing? B, how to reduce friction?

Friction is sometimes beneficial and sometimes harmful. So sometimes we have to increase friction, and sometimes we have to find ways to reduce friction. How to increase friction in theory? How to reduce friction?

Students answer the teacher's summary and write it on the blackboard. (omitted)

4, study the friction on the bicycle:

How much do you know about the friction on bicycles through today's study? Please discuss, compare and race in groups to see which group knows the most. Move a bike from outside the classroom.

The students pointed to bicycles, and the discussion was very lively.

5, the expansion of knowledge.

Due to friction, the speed of the vehicle is limited. Can you think of a way to speed up?

The students answered.

This paper introduces hydrofoil, hovercraft and maglev train.

Third, homework

Scientific paper: a world without friction

Get information about how hovercraft and maglev train can reduce friction.

Reflection after class:

This lesson introduces new lessons with concrete examples in daily life, which stimulates students' desire for learning and embodies the transition from life to physics. When exploring "factors affecting sliding friction", students are arranged to guess, design experiments, explore experiments and cooperate and communicate, so that students can experience the process of exploring the relationship between sliding friction and contact surface pressure and roughness. It well embodies the spirit that the new textbook allows students to actively acquire knowledge in the process of experiencing the formation and development of knowledge. After obtaining the knowledge about friction through experiments, we pay attention to guiding students to analyze and explain a large number of friction phenomena in life and production by using what they have learned, and also introduce the contents closely related to modern science and technology such as maglev train and hovercraft. It well embodies the concept of "from life to physics, from physics to society" in the new curriculum.

In teaching, teachers guide students to cite examples of friction in life, and then inspire students to guess what factors affect friction. After the student told his guess, they asked him, "Why do you think so? Let the students realize that the guess should be well-founded. Then organize students to explore their own guesses: we divide the class into several groups and conduct exploratory experiments to verify whether the guesses are correct. Then there are plans and experiments. There may be more than one factor to guide students to pay attention to the magnitude of sliding friction. If we want to study the influence of pressure change on sliding friction, how should we design experiments to know that the change of sliding friction is caused by this factor, not by other factors?

Let students be more familiar with the "control variable method" and use the control variable method to design experiments. Ask the students to talk about his design ideas. After thinking, students discuss and communicate, and teachers participate in a group of experimental designs. After completion, ask another group of students to talk about their experimental design and give them appropriate guidance and guidance.

After the experiment, let each group exchange the information and conclusions of the experiment and organize students to discuss. Whether the students' guesses are consistent with the experimental conclusions or not is an encouragement and affirmation of their spirit of seeking truth from facts.

Finally, the teacher guides the students to summarize the factors that affect the sliding friction: the roughness and pressure of the contact surface, so as to achieve a * * * understanding.