Objectives (5 - 7 minutes)

1. Understand the concept of electric force, its nature, and how it acts between two electric charges. This includes understanding Coulomb's law, which describes the force between two stationary charges.
2. Apply Coulomb's law to solve problems involving electric forces. Students should be able to calculate the electric force between two charges when provided with the magnitude of the charges and the distance between them.
3. Develop problem-solving skills, including the ability to interpret the problem, identify the appropriate formula, and perform the necessary calculations.

Secondary objectives:

• Identify the quantities involved in the calculation of electric force (charges and distance) and how they affect the final result.
• Recognize the importance and application of electric force in everyday situations.
• Promote teamwork and effective communication during problem-solving.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher should review the concepts of electric charge, Coulomb's law, and electric field that were covered in previous classes. This can be done through a quick oral review, asking students to briefly explain what they remember about these topics. (3 - 5 minutes)

2. Problem situations: The teacher should present two situations involving electric force, but without indicating how to solve them. For example, students can be asked how the electric force between two charges changes if the distance between them is doubled, or how the electric force between two charges changes if the magnitude of one of the charges is tripled. These questions are intended to spark students' interest and prepare them for the content that will be covered in the lesson. (2 - 3 minutes)

3. Contextualization: The teacher should explain to the students the importance of electric force, presenting examples of how it is applied in real situations. For example, one can talk about how electric force is fundamental for the operation of electronic devices, such as cell phones and computers. (2 - 3 minutes)

4. Topic introduction: The teacher should introduce the topic of the lesson, Electricity: Problems of Forces and Electric Fields, explaining that students will learn to apply Coulomb's law to solve problems involving electric forces. To spark students' interest, the teacher can share some curiosities or stories related to the topic. For example, one can talk about how the discovery of electricity changed the world, or about the life and contributions of Charles-Augustin de Coulomb, the scientist who formulated Coulomb's law. (3 - 4 minutes)

Development (20 - 25 minutes)

1. Experiment Construction Activity (10 - 12 minutes):

   • Group division: Students will be divided into small groups of 4 to 5 people. Each group will receive an experimentation kit containing wires, batteries, small metal spheres, and a distance meter.
   • Activity description: The teacher should explain that students will conduct an experiment to observe the electric force between two charges. Each group will assemble an 'electric pendulum' using the metal spheres and wires, which will be charged with opposite electric charges. The distance meter will be used to vary the distance between the charges. Students should observe and record the changes in the pendulum's movement as the distance between the charges is altered.
   • Experiment execution: Students will work together to assemble and conduct the experiment. They must ensure that the spheres are charged with opposite electric charges and that the distance between them is varied in a controlled manner. They should observe and record their observations as the distance between the charges is altered.
   • Results discussion: After conducting the experiment, the groups should discuss their results. The teacher should guide the discussion, asking questions to help students relate their observations to Coulomb's law.

2. Problem-Solving Activity (10 - 13 minutes):

   • Problem presentation: The teacher should present a problem of solving electric forces involving Coulomb's law. For example, students can be asked to calculate the electric force between two charges of 2 C and 3 C separated by a distance of 10 m.
   • Group discussion: Students, now familiar with Coulomb's law through the experiment, should discuss the problem in their groups and try to solve it. They should identify the quantities involved (charges and distance) and apply the Coulomb's law formula to calculate the electric force.
   • Presentation of solutions: After the group discussion, each group should present their solution to the problem. The teacher should correct the solutions if necessary and provide feedback to the students.
   • Final reflection: The teacher should lead a final discussion, asking students to reflect on what they learned in the lesson. They should share what they found most interesting or challenging and how they plan to apply what they learned in the future.

3. Simulation Game Activity (optional - 5 minutes):

   • If time allows, the teacher can propose a simulation game where students, using a physics app or an online simulation program, can explore different situations involving electric forces. The goal is to provide students with a practical and playful experience of how electric force behaves in different scenarios.
   • The teacher should guide the students during the game, asking questions to stimulate reflection and understanding of the concepts. For example, students can be asked to predict what will happen to the electric force if the magnitude of the charges increases, or if the distance between the charges decreases.

Return (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes):

   • The teacher should invite each group to share the solutions or conclusions they reached during the practical activities. Each group will have up to 3 minutes to present. During the presentations, the teacher should encourage other students to ask questions or make comments.
   • After each presentation, the teacher should provide a brief summary, highlighting the key points of the solutions or discoveries presented by the groups. This will help reinforce the concepts and facilitate understanding for all students.

2. Connection with Theory (2 - 3 minutes):

   • The teacher should revisit the theoretical concepts discussed at the beginning of the lesson and relate them to the practical activities carried out by the students. For example, one can discuss how Coulomb's law was applied to solve problems of electric forces, or how the observations from the experiments align with the theory.
   • The teacher should emphasize the importance of practice for understanding theory, and how theory helps explain the phenomena observed in practice. This will help students realize the relevance and applicability of the concepts learned.

3. Individual Reflection (1 - 2 minutes):

   • The teacher should propose that students reflect individually on what they learned in the lesson. They should think about the following questions:
     1. What was the most important concept learned today?
     2. What questions have not been answered yet?
   • Students will have a minute to reflect and then will be invited to share their answers. The teacher should encourage all students to participate, ensuring that everyone has the opportunity to speak.

4. Feedback and Closure (2 - 3 minutes):

   • The teacher should thank the students for their participation and effort during the lesson. He should emphasize the importance of feedback and reflection for the learning process, and encourage students to continue studying and asking questions.
   • The teacher should also ask for feedback from the students about the lesson, asking what they liked most and what they would like to see more in future lessons. This will help the teacher adjust and improve his future lessons.
   • Finally, the teacher should give a brief Introduction to the topic of the next lesson, preparing the students for what is to come and sparking their interest.

Conclusion (5 - 7 minutes)

1. Summary of Contents (2 - 3 minutes):

   • The teacher should recap the main points covered in the lesson. This includes the concept of electric force, Coulomb's law, and how to apply this law to solve problems of electric forces.
   • He should review the experiments conducted and the problem-solving activities, emphasizing the connection between theory and practice.
   • The teacher should also highlight the main results or conclusions obtained by the students during the lesson.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes):

   • The teacher should explain how the lesson connected theory, practice, and applications. He should highlight how the theoretical understanding of the concepts of electric force and Coulomb's law helped students understand and solve practical problems.
   • He should also reinforce the applicability of these concepts, mentioning again examples of how electric force is used in everyday situations, such as in the operation of electronic devices.

3. Additional Materials (1 minute):

   • The teacher should suggest extra materials for students who wish to deepen their knowledge on the topic. These materials may include books, articles, educational videos, simulation websites, and online exercises.
   • He should also remind students to review their notes and redo the exercises solved during self-study.

4. Relevance of the Topic (1 - 2 minutes):

   • Finally, the teacher should emphasize the importance of the lesson topic for everyday life and other disciplines. He can reinforce how electricity and electric forces are fundamental for the operation of many devices we use daily, such as cell phones and computers.
   • The teacher should also mention how understanding electric forces can be useful in other disciplines, such as chemistry, biology, and engineering. For example, understanding electric force is crucial to comprehend chemical processes, such as the bonding between atoms to form molecules, or to understand the operation of electrical circuits in engineering applications.