Lesson Plan | Active Learning | Dynamics: friction force

Assumptions: This Active Lesson Plan assumes: a 100-minute class, prior student study with both the Book and the start of Project development, and that only one activity (among the three suggested) will be chosen to be conducted during the class, as each activity is designed to take up a significant portion of the available time.

Objectives

Duration: (5 - 10 minutes)

The objectives stage is crucial for directing the focus of students and the teacher towards the learning goals of the lesson. By clearly establishing what is expected for students to learn, this section serves as a guide for subsequent activities, ensuring that all participants are aligned and prepared to achieve the desired outcomes.

Main Objectives:

1. Ensure that students are able to clearly differentiate between static friction and kinetic friction, understanding the conditions under which each type of friction acts.

2. Develop the ability to calculate static and dynamic friction forces in practical situations, using the formula F=µN.

Side Objectives:

1. Stimulate students' critical thinking by applying physics concepts to practical and real-life situations.
2. Encourage collaboration among students during practical activities, promoting peer learning.

Introduction

Duration: (15 - 20 minutes)

The introduction serves to engage students with the lesson's theme, using problem situations to revive prior knowledge and stimulate curiosity. The contextualization helps to connect theoretical concepts with the real world, increasing interest and relevance of the study of friction. This moment prepares students for practical activities, ensuring they are motivated and understand the importance of what will be learned.

Problem-Based Situations

1. Imagine a car trying to leave a parking lot with a slightly inclined ramp due to recent snow. The driver accelerates, but the wheels continue to spin in place. What is causing this lack of movement?

2. Consider a physics book placed on a table. When attempting to slide the book to the side, one realizes that an initial effort greater than what is needed to keep it moving is required. How can this behavior be explained based on the concepts of static and dynamic friction?

Contextualization

The study of friction is fundamental not only to physics but also to numerous practical applications in engineering, industrial design, and even sports. Understanding the differences between static and dynamic friction can be illustrated in everyday situations, such as trying to move a heavy piece of furniture or braking a vehicle on slippery roads. These real situations help to visualize the importance of friction and how it influences our actions and daily decisions.

Development

Duration: (75 - 80 minutes)

The development stage is designed to allow students to apply the concepts of static and dynamic friction in practical and playful situations. This section aims to solidify theoretical understanding through experimentation and group collaboration, promoting problem-solving and the application of physical calculations in real contexts. Each activity is structured to stimulate critical thinking and creativity, while students work together to solve concrete challenges.

Activity Suggestions

It is recommended to carry out only one of the suggested activities

Activity 1 - Challenging Friction: The Mystery of the Stuck Cart

> Duration: (60 - 70 minutes)

- Objective: Understand in practice the differences between static and kinetic friction and how variables like surface and weight affect an object's movement.

- Description: Students will be divided into groups, and each group will receive an 'experimental cart' (a toy cart adapted with different surfaces and weights). They should investigate and explain why the cart cannot move under different conditions of surface, slope, and weight, using the concepts of static and kinetic friction.

- Instructions:

• Form groups of up to 5 students.

• Receive an adapted cart and a set of different surfaces and weights.

• Test the cart in different scenarios and record results.

• Identify the static and kinetic friction forces acting on the cart in each scenario.

• Prepare a presentation to explain results and their relation to the concepts studied.

Activity 2 - The Great Sliding Books Challenge

> Duration: (60 - 70 minutes)

- Objective: Apply the formula F=µN to calculate static and kinetic friction in a practical situation, promoting understanding of physics concepts.

- Description: In this activity, students will explore static and kinetic friction by trying to move books on different surfaces. The challenge will be to determine the coefficient of friction and compare static and kinetic friction in various situations.

- Instructions:

• Organize into groups of up to 5 students.

• Receive a set of books and different surfaces to test.

• Use a dynamometer to measure the force required to move the books on different surfaces.

• Calculate the friction coefficient and compare with theoretical values.

• Prepare a report that includes graphs, calculations, and conclusions about the different types of friction.

Activity 3 - The Skater's Escape: Investigating Friction on Ice

> Duration: (60 - 70 minutes)

- Objective: Understand how dynamic friction varies with different materials and conditions, applying the concept of friction in a sports context.

- Description: Students will simulate the movement of a skater on ice and explore the conditions affecting dynamic friction. They will use skater models and different types of 'ice' (different materials and amounts of dry ice) to test how kinetic friction varies.

- Instructions:

• Form groups of up to 5 students.

• Each group receives a skater model and materials to simulate ice.

• Experiment with different combinations of skaters and 'ice' surfaces.

• Measure the distance traveled under different conditions and record observations.

• Calculate the kinetic friction coefficient in each scenario and discuss variations.

Feedback

Duration: (15 - 20 minutes)

The purpose of this feedback stage is to consolidate the learning gained during the practical activities, allowing students to articulate and share their understandings. Through discussion, students have the opportunity to reflect on the learning process, clarify doubts, and, most importantly, recognize the applicability of the concepts of static and dynamic friction in real situations. This exchange of ideas facilitates the internalization of concepts and prepares students for future applications of them.

Group Discussion

After the practical activities are completed, gather all students for a group discussion. Start the discussion with a brief recap of the concepts of static and dynamic friction. Encourage each group to share their discoveries and observations, focusing on how they applied the formulas and theories to solve the proposed challenges. Use targeted questions to ensure that all important aspects have been considered.

Key Questions

1. What were the main challenges encountered when trying to differentiate and calculate static and kinetic friction in practical activities?

2. How did variations in surfaces and weights affect the results of the experiments with friction?

3. In what ways can understanding static and dynamic friction be applied in everyday situations or other areas of physics?

Conclusion

Duration: (5 - 10 minutes)

The purpose of the conclusion stage is to ensure that students have consolidated the knowledge acquired during the lesson, linking theory and practice in a clear and meaningful way. Recapping key points helps reinforce memory and understanding of students, while discussing the applicability of the concepts reinforces the importance of what was learned. This stage is crucial to ensure that students can transfer the knowledge acquired to new situations and contexts, as well as prepare them for future studies and practical applications.

Summary

In the conclusion, the teacher should summarize and recap the main concepts discussed about static and dynamic friction, emphasizing the formulas and conditions of application for each type of friction. It is crucial that students have a clear view of what was learned during the lesson, reinforcing the importance of differentiating and calculating the forces of static and kinetic friction.

Theory Connection

Today's lesson was structured to connect theory and practice in an integrated manner. Through experimental activities, students were able to directly apply the formulas and theoretical concepts in practical situations, allowing for a deeper and more tangible understanding of physical phenomena. This approach not only facilitated learning but also demonstrated the relevance of the concepts of static and dynamic friction in everyday contexts and industrial applications.

Closing

Finally, it is essential to highlight the importance of studying friction. Understanding these concepts not only enriches theoretical knowledge in physics but is also fundamental to various practical applications, from developing technologies to safety in daily activities. The ability to predict and manipulate friction forces can lead to significant improvements in many aspects of everyday and professional life.