Objectives

(5 - 7 minutes)

1. Understand momentum:

   • Students should be able to define and explain momentum (or linear momentum) of an object or system of objects in terms of its mass and velocity.
   • Students should understand that momentum is a vector quantity, meaning it has magnitude and direction.

2. Apply the law of conservation of momentum:

   • Students should be able to apply the law of conservation of momentum in different collision situations, both elastic and inelastic.
   • They should understand that in an isolated system, the total momentum before and after the collision is the same.

3. Solve problems involving momentum:

   • Students should be able to solve physics problems involving momentum, applying the formulas and concepts learned.
   • They should be able to identify relevant information in a problem and choose the correct strategy to solve it.

Secondary Objectives:

• Develop critical thinking and problem-solving skills:

  • Throughout the learning process, students will develop critical thinking and problem-solving skills, which are essential not only for physics but for all areas of life.

• Foster active participation and collaboration in the classroom:

  • The flipped classroom model encourages active participation and collaboration among students. They will have the opportunity to discuss concepts, work on problems together, and learn from each other.

Introduction

(10 - 15 minutes)

1. Review of previous concepts:

   • The teacher should review the concepts of mass and velocity, which are essential for understanding momentum. A brief review of velocity and acceleration calculations can be done so that students are familiar with the formulas needed for the lesson.

2. Problem situations:

   • The teacher can present two problem situations to instigate students' curiosity and introduce the topic. For example:
     • 'Imagine a Formula 1 car at high speed. What would happen if it crashed into a concrete wall? And if it collided with another Formula 1 car at the same speed?'
     • 'If you were skating on ice and threw a heavy object backwards, would you move forward faster or slower? Why?'

3. Contextualization:

   • The teacher should explain the importance of studying momentum, showing how it applies in everyday situations and in various areas of science and engineering. For example, in particle physics, in car collision engineering, in human movement biomechanics, among others.

4. Introduction to the topic:

   • The teacher should introduce the concept of momentum, explaining that it is the measure of how difficult it is for an object to stop or change speed.
   • It can be mentioned that momentum is a vector quantity, meaning it has magnitude and direction, and that its unit in the International System is kg.m/s.
   • The teacher can give a practical example, such as a soccer player kicking a ball. If the ball is light but the kick is strong, the ball will move quickly (high momentum). If the ball is heavy and the kick is weak, the ball will move slowly (low momentum).

Development

(20 - 25 minutes)

1. Activity 'Air Collisions':

   • Divide the class into groups of up to 5 students. Each group will receive:

     • A wooden ruler approximately 30 cm long.
     • Two plastic toy cars, preferably of different sizes.
     • Small clay masses to place on the cars and change their masses.
     • A stopwatch.

   • The objective of the activity is for students to simulate collisions between toy cars in the air, without the interference of gravity. They should vary the mass of the cars and the initial velocity of one of them (by pushing it with the ruler) and observe what happens to the cars' velocity after the collision.

   • Students should record the mass and velocity data before the collision and the velocity after the collision. They should repeat the activity several times, changing the variables and observing the changes in the results.

   • During the activity, the teacher should circulate around the room, guiding the students, clarifying doubts, and encouraging discussion among group members.

2. Group Discussion:

   • After the conclusion of the activity, each group should present their results to the class. They should explain the observations they made and try to relate them to the concepts of momentum and conservation of momentum.

   • The teacher should facilitate the discussion by asking guiding questions and helping students make the necessary connections. For example: 'How did mass and initial velocity affect the final velocity of the cars?' 'Was momentum conserved in all collisions? Why?'

3. Activity 'Momentum Problems':

   • After the discussion, the teacher should distribute a sheet of problems involving momentum. The problems should be varied and challenging, but within the students' ability to solve with the tools they have learned.

   • Students should work in their groups to solve the problems. The teacher should circulate around the room, assisting students who are having difficulties and encouraging collaboration among groups.

   • After a set time, each group should present their solutions to the problems. The teacher should correct errors, clarify doubts, and reinforce important concepts.

4. Conclusion of the Activity:

   • To conclude the activity, the teacher should summarize the main points discussed and reinforce the concepts of momentum and conservation of momentum.

   • The teacher should also highlight the importance of critical thinking and problem-solving in the study of physics (and in all areas of life) and congratulate the students for their teamwork and active participation in the class.

5. Break:

   • After the conclusion of the activity, the teacher can propose a brief break so that students can rest, if necessary, and resume the class with renewed energy.

Return

(8 - 10 minutes)

1. Group Discussion:

   • The teacher should gather all students and promote a group discussion about the solutions presented by each group for the momentum problems. Each group can briefly present their solution, and the teacher can comment on the approaches used and the successes and mistakes made.

2. Connection with Theory:

   • The teacher should then make the connection between the practical activities carried out and the theory presented at the beginning of the class. They should explain how observing collisions in the air and solving momentum problems illustrate theoretical concepts in a practical and concrete way.

3. Individual Reflection:

   • The teacher should propose that students reflect individually on what they learned in the class. They can ask questions like: 'What was the most important concept you learned today?' and 'What questions have not been answered yet?' Students should write down their answers in a notebook or on a piece of paper.

4. Sharing Reflections:

   • After a minute of reflection, the teacher should ask some students to share their answers with the class. This can be done voluntarily or through a draw. The goal is to promote the exchange of ideas and mutual learning.

5. Teacher Feedback:

   • Based on the students' reflections and the group discussions, the teacher should give general feedback on the class. They can praise the positive aspects, such as active participation and problem-solving, and suggest areas for improvement, such as the need for more practice or the importance of reviewing certain concepts.

6. Preparation for the Next Class:

   • Finally, the teacher should prepare the students for the next class. They can give a brief overview of what will be studied and suggest additional study materials, such as readings or videos. The teacher should encourage students to review the concepts learned and come to the next class with questions and doubts to be discussed.

7. Closure:

   • To end the class, the teacher should thank everyone for their participation and effort, reinforce the importance of continuous study, and wish them a good day.

   • The teacher should be available to clarify any extra doubts or provide additional support, if necessary.

Conclusion

(5 - 7 minutes)

1. Recap of the main points:

   • The teacher should review the concepts of momentum and conservation of momentum, highlighting that an object's momentum is the product of its mass by its velocity and that, in an isolated system, the total momentum before and after the collision is the same.
   • It should be reinforced that momentum is a vector quantity, which has magnitude and direction, and that its unit in the International System is kg.m/s.

2. Connection between theory, practice, and applications:

   • The teacher should emphasize how the practical activities carried out in the class, such as simulating collisions in the air and solving momentum problems, allowed students to understand theoretical concepts in a practical and applied way.
   • It should also be highlighted how the study of momentum has important practical applications, such as in particle physics, car collision engineering, human movement biomechanics, among others.

3. Extra Materials:

   • The teacher can suggest additional study materials for students who wish to deepen their knowledge of momentum. A physics textbook, science websites, educational videos, among others, can be recommended.
   • The teacher should remind students that continuous review of concepts and practice in problem-solving are essential for effective learning of physics.

4. Importance of the subject:

   • Finally, the teacher should summarize the importance of studying momentum.
   • It should be emphasized that understanding this concept allows predicting and explaining the movement of objects and systems of objects, and is fundamental for the study of other areas of physics, such as kinematics, dynamics, and thermodynamics.
   • The teacher can also mention that the ability to apply the law of conservation of momentum in different situations is a valuable skill not only in physics but in many other areas of life, such as in problem-solving, decision-making, and critical thinking.