Objectives (5-7 minutes)

1. Understand the concept of potential elastic energy: Students should be able to define and explain the concept of elastic potential energy, understanding how it is stored in a deformed body, such as an elastic, and released when the body returns to its original shape.

2. Calculate the potential elastic energy: Students should learn to calculate the potential elastic energy of a deformed body using the formula E = 1 / 2kx ^ 2, where E is the potential elastic energy, k is the elastic constant of the body, and x is the deformation.

3. Apply the potential elastic energy in problem situations: Students should be able to apply the concept of elastic potential energy in real or hypothetical situations, solving problems that involve determining the deformation of a body or the elastic constant from the elastic potential energy.

Secondary objectives:

• Develop critical thinking and problem solving: By working with potential elastic energy, students will have the opportunity to develop critical thinking and problem-solving skills, which are fundamental to studying physics and many other areas of knowledge.

• Encourage teamwork and collaboration: The planned practical activities in the classroom will allow students to work in groups, encouraging collaboration and exchange of ideas, which are essential for the development of socio-emotional skills.

Introduction (10-15 minutes)

1. Review of previous contents: The teacher should recall the concepts of energy, work and force, which were previously studied, as they are fundamental to understanding the concept of potential elastic energy. In addition, the teacher should reinforce the importance of studying these concepts, as they are fundamental to understanding many natural and technological phenomena.

2. Problem situations: The teacher can present two situations to arouse students' interest and introduce the theme of the lesson. The first situation could involve launching a projectile using a slingshot. The question would be: "Where does the energy that makes the projectile fly come from?" The second situation could involve the functioning of a string-driven clock. The question would be: "How is the energy stored in the clock's cord and released to move the gears?"

3. Contextualization: The teacher should explain that elastic potential energy is a fundamental concept in physics and has practical applications in many areas, such as engineering, architecture, medicine, and sports. For example, elastic potential energy is used in the design of car springs, in the construction of bridges and buildings, in the creation of prostheses and in many sports, such as high jump and pole vault.

4. Introduction to the topic: To arouse students' curiosity, the teacher can present some curiosities about potential elastic energy. For example, the teacher can mention that elastic potential energy is used in the development of innovative technologies, such as exoskeletons for people with difficulty in locomotion. In addition, the teacher can show a video of an experiment in which an elastic band is stretched and releases enough energy to make a toy car move, demonstrating the amount of energy that can be stored in an elastic band.

Development (20-25 minutes)

1. Practical Activity 1 - "Elasto track" (10-12 minutes)

   • Objective: The purpose of this activity is for students to understand experimentally how elastic potential energy is stored in a deformed body and released when the body returns to its original shape.

   • Materials: Elastics of different sizes and thicknesses, ruler, scale.

   • Procedure:

     1. Students, organized in groups of no more than 5, receive an elastic band and must measure its original length and its deformation when stretched.
     2. Using the scale, students should measure the force required to stretch the elastic band.
     3. The students should then release the elastic band and observe how it returns to its original shape, releasing the potential elastic energy.
     4. Students repeat the procedure with elastics of different sizes and thicknesses, recording the data obtained.
     5. Finally, students should discuss and record their observations, relating them to the concept of potential elastic energy.

2. Practical Activity 2 - "Elastic Calculation" (10-12 minutes)

   • Objective: The purpose of this activity is for students to apply the concept of elastic potential energy in problem solving, calculating the deformation of a body from the potential elastic energy.

   • Materials: Printed problems, pencils, calculator.

   • Procedure:

     1. Students, still in groups, receive problems involving the calculation of the deformation of a body from the elastic potential energy. For example: "A body with a mass of 1 kg is attached to a spring, which has an elastic constant of 10 N / m. If the spring is stretched 0.2 m, what is the deformation of the body? ".
     2. Using the formula E = 1 / 2kx ^ 2, students should calculate the potential elastic energy of the body and then the deformation of the body.
     3. Students should record the calculations and discuss the solutions in a group.
     4. The teacher should circulate around the room, assisting the groups who encounter difficulties in solving the problems.

3. Practical Activity 3 - "Elasto Challenge" (5-7 minutes)

   • Objective: The purpose of this activity is for students to apply the concepts learned in potential elastic energy and problem solving in a fun and challenging challenge.

   • Materials: Elastics of different sizes and thicknesses, light objects, stopwatch.

   • Procedure:

     1. Students, still in groups, are challenged to build a "slingshot" that can launch a light object (e.g., a paper ball) at a given distance.
     2. Students should plan the building of the "slingshot" and estimate the potential elastic energy that will be required to launch the object to the desired distance.
     3. Then the students build the "slingshot" and perform the launch, measuring the distance reached with the object.
     4. Students should compare the distance achieved with the estimated distance and discuss possible sources of error.
     5. Finally, students should record the results and conclusions of the challenge.

These practical activities will allow students to understand the concept of potential elastic energy in a concrete and contextualized way, developing observation, experimentation, calculation and problem-solving skills.

Feedback (10-12 minutes)

1. Group Discussion (3-4 minutes)

   • Objective: The purpose of this step is for students to share the solutions and conclusions they found during the practical activities, promoting the exchange of ideas and collaborative learning.

   • Procedure:

     1. The teacher should promote a group discussion, where each team will have the opportunity to briefly present their solutions and conclusions.
     2. During the presentation, the teacher should encourage the participation of all students, asking questions to ensure everyone's understanding of the concept of potential elastic energy.
     3. The teacher should highlight the positive points of each presentation and, if necessary, make corrections or additions.

2. Connection with the Theory (3-4 minutes)

   • Objective: The purpose of this step is for the teacher to link the practical activities carried out with the theory presented at the beginning of the lesson, reinforcing the students' understanding of the concept of potential elastic energy.

   • Procedure:

     1. The teacher must recall the definition of potential elastic energy and the formula for its calculation, relating them to the observations and calculations made by students during the hands-on activities.
     2. The teacher should emphasize how potential elastic energy is stored in a deformed body and released when the body returns to its original shape, reinforcing the idea that energy is neither created nor destroyed, only transformed.
     3. The teacher should emphasize the importance of the concept of potential elastic energy in understanding many natural and technological phenomena, reinforcing the relevance of studying physics.

3. Individual Reflection (3-4 minutes)

   • Objective: The aim of this step is for students to reflect individually on what they have learned in the lesson, identifying the most important concepts and possible difficulties.

   • Procedure:

     1. The teacher should propose that the students reflect individually on the following questions: "What was the most important concept you learned today?" and "What were the main difficulties you faced? ".
     2. Students will have one minute to think about the questions and then be invited to share their answers with the class.
     3. During sharing, the teacher should value students' responses, reinforcing the importance of self-knowledge and reflection in learning.

This Feedback step is essential for consolidating students' learning, as it allows them to reflect on what they have learned, share their ideas and doubts, and receive feedback from the teacher. In addition, it promotes the development of communication, reflection and critical thinking skills.

Conclusion (5-7 minutes)

1. Summary and Recapitulation (2-3 minutes)

   • Objective: The teacher should summarize the main points covered during the class, recalling the definition of potential elastic energy, the formula for its calculation and the practical applications of this concept.

   • Procedure:

     1. The teacher should begin the review by recalling the importance of studying energy, work and force, which were reviewed concepts at the beginning of class.
     2. Then, the teacher should review the concept of potential elastic energy, explaining again how it is stored in a deformed body and released when the body returns to its original shape.
     3. The teacher should summarize the formula for calculating potential elastic energy, E = 1 / 2kx ^ 2, reinforcing the importance of understanding each of the terms in the formula.
     4. Finally, the teacher should summarize the practical applications of potential elastic energy, highlighting how it is used in various areas, such as engineering, architecture, medicine and sports.

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

   • Objective: The teacher should emphasize how the class connected the theory, practice and applications of the concept of potential elastic energy.

   • Procedure:

     1. The teacher should explain how the practical activity "Elasto track" allowed students to understand experimentally how the potential elastic energy is stored in a deformed body and released when the body returns to its original shape.
     2. The teacher should emphasize how the "Elastic Calculation" practical activity allowed students to apply the potential elastic energy concept to problem solving.
     3. The teacher should highlight how the "Elasto Challenge" challenge allowed students to apply the concepts learned from potential elastic energy and problem solving in a real and fun situation.
     4. Finally, the teacher should reinforce the importance of understanding the theory, practicing with experimental activities and problem solving, and understanding the applications of the concept for effective learning.

3. Supplementary Material (1-2 minutes)

   • Objective: The teacher should suggest supplementary materials for students who wish to deepen their understanding of the concept of potential elastic energy.

   • Procedure:

     1. The teacher may suggest reading chapters or sections of textbooks that cover the concept of potential elastic energy.
     2. The teacher may indicate videos, websites, or interactive applications that explain the concept in a visual and dynamic way.
     3. The teacher may suggest solving extra problems that allow students to further practice calculating potential elastic energy and solving problems involving this concept.

4. Importance of the Topic in Everyday Life (1 minute)

   • Objective: The teacher should end the class by emphasizing the importance of the potential elastic energy concept on a daily basis, reinforcing the relevance of studying physics.

   • Procedure:

     1. The teacher may mention some everyday situations in which potential elastic energy is present, such as stretching an elastic band, jumping on a trampoline, or using a string-driven clock.
     2. The teacher can explain that studying physics, and in particular the concept of energy, allows us to understand and explain many natural and technological phenomena, contributing to the development of critical thinking and problem-solving skills.

At the end of the class, students should have consolidated their understanding of the concept of potential elastic energy, be able to calculate the potential elastic energy of a deformed body and apply this concept in solving problems. In addition, students should have understood the importance of this concept and the study of physics for their daily lives and for society in general.