Objectives (5 - 7 minutes)

1. Understanding the Concept of Gravitation and Gravitational Force: Students should understand what gravitation is, how it acts, and what gravitational force is. They should be able to differentiate between gravitation and gravitational force.

2. Application of Gravitation Formulas: Students should be able to apply the formula for gravitational force between two bodies to solve problems. They should understand how the variables in the formula affect the resulting force.

3. Solving Practical Gravitation Problems: Students should be able to solve practical gravitation problems, such as calculating the gravitational force between two bodies of different masses.

Secondary Objectives

1. Development of Critical Thinking: While solving gravitation problems, students should develop the ability to critically analyze the problem, identify relevant information, and apply the acquired knowledge to reach a solution.

2. Encouragement of Teamwork: During practical activities, students should be encouraged to work in teams, sharing and discussing ideas for problem-solving.

Introduction (10 - 15 minutes)

1. Review of Previous Concepts: The teacher should start the lesson by reviewing the concepts of mass, weight, and force, which are necessary for a complete understanding of the topic of gravitation. He should remind students about the difference between mass and weight, and how force is measured and calculated. (2 - 3 minutes)

2. Problem Situation: Next, the teacher can propose two problem situations to spark the students' interest:

   • Situation 1: 'Imagine you are on a planet where gravity is twice that of Earth. If you weigh 50 kg on Earth, how much would you weigh on this planet?'
   • Situation 2: 'Two objects of different masses are at a certain distance from each other in space. How would you calculate the gravitational force between them?' (3 - 5 minutes)

3. Contextualization: The teacher should then explain the importance of studying gravitation, showing how this universal law of physics applies to various aspects of everyday life and the universe. Some examples could be:

   • How gravitation keeps planets in orbit around the sun.
   • How gravitation is essential for the formation and evolution of the universe.
   • How gravitation is used in technology, such as in communication satellites and space telescopes. (2 - 3 minutes)

4. Introduction to the Topic: To introduce the topic of gravitation in an engaging way, the teacher can share some related curiosities or stories:

   • Curiosity 1: 'Did you know that the force of gravity on the surface of Jupiter, the largest planet in our solar system, is more than twice that of Earth? This means that if you weigh 50 kg on Earth, you would weigh over 100 kg on Jupiter!'
   • Curiosity 2: 'Have you heard of the legend of the apple that fell on Isaac Newton's head, leading him to discover the law of gravitation? The story may not be true, but Newton's discovery revolutionized physics!' (3 - 5 minutes)

Development (20 - 25 minutes)

1. Simulation Activity: 'Gravitating!'

   • Description: In this activity, students will simulate the orbits of planets around the sun. They will understand how gravitational force acts to keep the planets in their respective orbits.

   • Materials: Tennis balls (to represent the planets) and a basketball (to represent the sun). Nylon strings (to 'suspend' the planets in the orbits).

   • Step by Step:

     1. First, the teacher should distribute the materials and divide the class into groups of 3 to 4 students.
     2. Next, each group should choose a planet from the solar system to represent.
     3. Students should determine the mass of their 'planet' compared to the basketball (the sun). For example, if the basketball represents Earth, a tennis ball can represent Mars (with a smaller mass).
     4. Using the nylon strings, students should 'suspend' their planets in their orbits around the 'sun' (the basketball), according to the determined mass scale.
     5. Students should observe how, even with different masses (represented by the tennis balls), all planets remain in their orbits due to the force of gravity.
     6. During the activity, students should discuss in their groups about the importance of mass and gravitational force in the formation of orbits.

2. Problem-Solving Activity: 'The Mystery of the Missing Planets'

   • Description: In this activity, students will solve a gravitation problem involving the gravitational force between two bodies. They will apply the gravitation formula to determine the mass of an unknown planet based on its gravitational attraction to another planet.

   • Materials: Printed problem, calculators.

   • Step by Step:

     1. The teacher should hand out the printed problem to each group of students.
     2. Students should read the problem and identify the relevant information. They should understand that the gravitational force between two bodies depends on their masses and the distance between them.
     3. Using the gravitation formula, students should solve the problem to determine the mass of the unknown planet.
     4. Students should discuss and verify their solutions with the teacher.
     5. The teacher should guide a class discussion on the problem-solving, highlighting key steps and the application of the concept of gravitational force.

3. Discussion Activity: 'Gravity in Other Worlds'

   • Description: In this activity, students will discuss and present how life would be on a planet with a gravity different from Earth.

   • Materials: None.

   • Step by Step:

     1. The teacher should divide the class into groups and assign each group a planet or moon from the solar system with significantly different gravity from Earth (for example, Jupiter, with more than twice the gravity, or the Moon, with about one-sixth of Earth's gravity).
     2. Each group should discuss and present how life would be on that planet in terms of movement, weight, daily activities, construction, etc.
     3. After the presentations, the teacher should facilitate a class discussion on the different perceptions and understandings of the students about gravity.

Return (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes): The teacher should gather all students in a circle or semicircle and promote a group discussion. Each group will have up to 2 minutes to share the solutions or conclusions they reached in the activities. During the presentations, the teacher should ensure that all students are involved, asking questions and encouraging debate.

2. Connection to Theory (2 - 3 minutes): After all groups have shared, the teacher should make the connection between the practical activities and the theory of gravitation. He should highlight how the concepts of gravitational force and its application were demonstrated in the activities. The teacher can also highlight any common mistakes students may have made and explain the correct way to approach these problems.

3. Individual Reflection (2 - 3 minutes): To conclude the lesson, the teacher should ask students to reflect individually on what they have learned. They should think about the following questions:

   1. What was the most important concept you learned today?
   2. What questions remain unanswered?
   3. How can you apply what you learned today in everyday situations or in other disciplines?

The teacher should allow a minute for students to think about each question. Then, he can ask some students to share their answers with the class. The goal of this reflection is to help students consolidate their learning and identify any areas that may need review or further clarification.

4. Teacher Feedback (1 minute): After the reflection, the teacher should briefly share his observations about the lesson. He should praise the students' efforts, highlight the strengths of the lesson, and offer suggestions for future improvements. The teacher should also encourage students to continue practicing the concepts learned at home and seek additional help if needed.

This is a crucial moment for the teacher to assess what was learned during the lesson and identify any gaps in students' understanding. He can also use this information to plan the next lesson and adapt his teaching approach as needed.

Conclusion (2 - 3 minutes)

1. Recap of Key Concepts (1 minute): The teacher should summarize the main points of the lesson, reminding students about the concepts of gravitation, gravitational force, application of formulas, and solving practical problems. He should emphasize the importance of understanding these concepts to comprehend how gravity works in the universe.

2. Connection between Theory, Practice, and Applications (30 seconds): The teacher should explain how the lesson connected the theory of gravitation with practice, through simulation activities and problem-solving. He should also reinforce how these concepts have practical applications, from understanding the movement of planets to space technology.

3. Suggestion of Extra Materials (30 seconds): To deepen students' understanding of the topic, the teacher can suggest additional reading materials or videos. Some examples could be documentaries about gravity in the universe, interactive computational simulations, or physics books that delve deeper into the theory of gravitation.

4. Importance of the Topic for Everyday Life (30 seconds): Finally, the teacher should emphasize the relevance of the topic for everyday life. He can explain that although gravity is an invisible and often overlooked force, it is always present and affects everything around us. From how we move on Earth to the structure of the universe, gravity plays a fundamental role in our lives and in our world.

This Conclusion moment is essential to consolidate students' learning and to motivate them to continue exploring the topic on their own. By providing an overview of the concepts learned, a connection to the real world, and suggestions for additional learning, the teacher can help students realize the importance and applicability of what they learned in today's class.