Objectives (5 - 10 minutes)

1. Understand the concept of waves and how they behave in a medium.

2. Understand what a vibrating string is and how it produces different sounds depending on the vibration frequency.

3. Apply the acquired knowledge to solve practical problems related to the topic, such as determining the frequency of a sound produced by a vibrating string.

Secondary Objectives:

• Develop critical thinking and problem-solving skills by applying physics concepts to practical situations.

• Promote interaction and collaboration among students through group learning activities.

Introduction (10 - 15 minutes)

1. Review of previous concepts:

   • The teacher should start the lesson by briefly reviewing the concepts of waves and vibrations that were studied in previous classes. This can be done through a quick classroom discussion or with the help of a diagram or visual presentation to reinforce the concepts.

2. Problem situations:

   • The teacher can present two problem situations to the students. The first could be: 'Why does a guitar produce different sounds when strings of different thicknesses are played in the same way?' The second problem situation could be: 'How can we determine the frequency of the sound that a guitar string produces when played?' These questions should be presented to stimulate critical thinking and curiosity among the students.

3. Contextualization:

   • The teacher can contextualize the importance of the topic, explaining how understanding waves and vibrations in strings is fundamental for music and acoustics. The importance of this knowledge for a luthier, for example, who needs to understand how the strings of a musical instrument vibrate to adjust the pitch and quality of the sound produced, can be mentioned.

4. Introduction of the topic:

   • The teacher should introduce the topic of the lesson, explaining that the students will learn about how waves behave in strings and how this affects the sound that the strings produce. To spark the students' interest, the teacher can share some curiosities, such as the history of the invention of the guitar and the piano and how these instruments were developed based on the understanding of waves and vibrations in strings.

Throughout the Introduction, the teacher should encourage active student participation by asking questions, requesting examples, and encouraging discussion. This will help ensure that students are engaged in learning from the beginning and are ready to explore the topic more deeply.

Development (20 - 25 minutes)

1. Simulation Activity with Strings and Cups:

   • The teacher will divide the class into groups of up to 5 students. Each group will receive a guitar string and two cups of different sizes.

   • The activity consists of creating different sounds by passing the string over the mouths of the cups and then varying the tension of the string by pulling it from side to side (similar to a guitar).

   • Students should observe how the change in string tension affects the sound produced and record their observations.

   • To complement the activity, the teacher can provide different types of strings (nylon, steel, etc.) so that students can compare how different materials also affect the sound produced.

   • After the activity, each group should share their observations with the class, explaining how the change in string tension affected the sound produced.

2. Frequency Analysis Activity:

   • For this activity, the teacher should prepare a series of videos of vibrating strings of different lengths and thicknesses in advance.

   • Each group of students will receive a video and a corresponding frequency graph.

   • The group's task is to analyze the video and determine the frequency of the vibrating string.

   • Students should use the frequency graph as a reference and apply the correct formula to calculate the frequency.

   • After the activity, each group should present their analysis to the class, explaining how they determined the frequency and discussing which factors can affect the frequency of a vibrating string.

3. Group Discussion:

   • To conclude the Development stage, the teacher should promote a group discussion where each group of students shares their findings and conclusions from the activities carried out.

   • The objective of this discussion is to allow students to learn from each other, reinforcing their understanding of the topic and enhancing their communication and collaboration skills.

These activities were designed to allow students to explore the topic of waves and vibrations in a practical and meaningful way. Through the manipulation of strings and the analysis of videos, students will have the opportunity to see and hear waves in action, making the topic more tangible and understandable. Additionally, by working in groups, students will have the chance to enhance their teamwork and communication skills.

Return (10 - 15 minutes)

1. Group Discussion:

   • The teacher should promote a whole-class discussion where each group of students shares their findings and conclusions from the activities carried out. The teacher should encourage students to explain their reasoning and present evidence to support their conclusions. This will help reinforce what students have learned during the practical activities.

2. Connection to Theory:

   • After the discussion, the teacher should make the connection between the practical activities and the theory of the topic. For example, the teacher can explain how the change in string tension affects the amplitude and, therefore, the intensity of the sound produced. Or how the frequency of a vibrating string is related to the length and tension of the string.

3. Individual Reflection:

   • The teacher should then ask students to reflect individually on what they learned in the lesson. To do this, the teacher can ask questions such as:
     1. What was the most important concept you learned today?
     2. What questions have not been answered yet?
     3. How can you apply what you learned today in everyday situations?

4. Collective Feedback:

   • After individual reflection, the teacher can ask some students to share their answers with the class. This can help identify which concepts need to be reinforced in future classes and clarify any misunderstandings.

5. Lesson Closure:

   • To conclude the lesson, the teacher should summarize the main points discussed and reinforce the key concepts. The teacher can also suggest additional reading or study materials for students who wish to explore the topic more deeply.

The Return is an essential part of the lesson plan, as it allows the teacher to assess the effectiveness of the lesson and the level of understanding of the students. Additionally, by promoting reflection and discussion, the Return helps consolidate learning and prepare students for future classes or independent studies.

Conclusion (5 - 10 minutes)

1. Recapitulation of Contents:

   • The teacher should start the Conclusion of the lesson by summarizing the main points covered during the lesson. This includes the definition of waves, the behavior of waves in a medium, the concept of vibrating strings, and how the vibration frequency of the string affects the sound produced.

2. Connection between Theory, Practice, and Applications:

   • Next, the teacher should highlight how the practical activities carried out during the lesson helped illustrate and consolidate the theoretical concepts presented. Practical applications of the topic, such as understanding how the strings of a musical instrument vibrate is crucial for sound production, should also be reinforced.

3. Supplementary Materials:

   • The teacher can suggest additional reading or study materials for students who wish to deepen their knowledge of the topic. This may include physics books, educational websites, explanatory videos, among others. For example, the teacher may recommend that students watch videos of luthiers explaining how they adjust the string height on a musical instrument.

4. Importance of the Subject:

   • To conclude, the teacher should emphasize the importance of the topic for everyday life and other areas of study. It can be mentioned, for example, how understanding waves and vibrations in strings is fundamental for music and acoustics, but also for other areas such as engineering and medicine (for example, in the creation of ultrasounds for medical diagnosis).

5. Encouragement for Autonomous Study:

   • Finally, the teacher should encourage students to continue studying the topic on their own. This may include additional readings, solving more problems related to the topic, exploring online simulations, among others. For example, the teacher may suggest that students experiment at home with a musical instrument and observe how the change in string tension affects the sound produced.

The Conclusion is a crucial stage of the lesson plan, as it allows the teacher to reinforce key concepts, establish connections between theory and practice, and motivate students to continue learning. By ending the lesson clearly and concisely, the teacher helps consolidate learning and prepare students for future classes or independent studies.