Objectives (10 - 15 minutes)

1. The students will understand the concept of gravitational force and its direction. They will learn that gravity always acts in a direction towards the center of mass.

2. The students will conduct a hands-on experiment to investigate the direction of the gravitational force. They will use common classroom materials to demonstrate how gravity pulls everything towards the center of mass.

3. The students will analyze and interpret the results of their experiment, making connections between their observations and the concept of gravitational force direction. They will apply their understanding to real-world examples, further cementing the concept.

Secondary objectives:

1. The students will improve their problem-solving skills by actively participating in the hands-on experiment and the subsequent analysis of the results.

2. The students will enhance their collaborative skills by working in groups during the experiment. They will learn to communicate their ideas effectively and work together towards a common goal.

3. The students will develop their critical thinking skills as they analyze the results of their experiment, making connections between their hands-on experiences and the theoretical concept of gravitational force direction.

Introduction (10 - 15 minutes)

1. The teacher begins by revisiting the concept of force, which the students have already learned about in previous lessons. In particular, the teacher emphasizes that forces have both a magnitude (how strong they are) and a direction (which way they are pulling or pushing). This serves as a foundation for understanding gravitational force.

2. Then, the teacher proposes two problem situations:

   • First, the teacher drops a pencil from a height and asks the students why it falls down instead of going up or sideways.
   • Second, the teacher shows a picture of a mountain climber and asks why the climber needs to exert more force to climb up than to come down.

3. Next, the teacher highlights the importance of understanding gravitational force direction in real-world applications. For example, in construction, engineers need to account for gravity to ensure buildings and bridges are stable. Astronauts and space scientists need to understand gravity to navigate spacecraft and plan space missions.

4. To introduce the topic of gravitational force direction, the teacher shares a fun fact: "Did you know that if you were to dig a hole through the center of the Earth and jump in, you would fall down at first, but then you would start falling up as you got closer to the other side? This is because gravity always pulls us towards the center of the Earth, which is the center of mass in this case."

5. The teacher then follows this with a story: "Once upon a time, Sir Isaac Newton was sitting under an apple tree when an apple fell on his head. This made him wonder why the apple fell straight down and not sideways or upwards. This led him to discover the law of gravity!"

6. Finally, the teacher formally introduces the lesson's topic: "Today, we will investigate the direction of the gravitational force. We will conduct a hands-on experiment to learn more about how gravity always pulls us towards the center of mass."

Development (20 - 25 minutes)

Activity 1: Gravity and Juggling

1. The teacher starts by explaining the activity: "Have you ever watched a juggler at a circus? Did you notice that no matter how high he throws the balls, they always come back down? That's gravity in action!"

2. The teacher then divides the class into groups of three to four students. Each group gets a set of juggling balls (or any other light, round objects if juggling balls are not available).

3. After the groups have been formed, the teacher walks the students through the steps:

   1. One student holds a ball above his or her head and drops it. The other students observe which way the ball falls.

   2. Another student throws a ball up in the air. The group observes and discusses where the ball goes.

   3. The same student now throws a ball sideways. The group should discuss where the ball goes and why it doesn’t continue moving sideways indefinitely but rather falls towards the ground.

4. The groups share their observations and conclusions. They connect their findings to the concept that gravity pulls everything towards the center of mass, in this case, the center of the Earth. They also draw the thought that the higher the object, the stronger it gets pulled by gravity and the faster it falls, directly aligning with the concept of gravitational force.

Activity 2: Gravity and Pendulum

1. The teacher introduces the second activity: "Now, we’re going to use a simple pendulum to further explore the direction of gravitational force."

2. The teacher provides each group with a simple pendulum made of a long piece of string with a small object tied to one end.

3. The teacher walks the students through the steps:

   1. Hang the pendulum from a fixed point. Let it stay still and note the position.
   2. Swing the pendulum and observe the movement.
   3. Let the pendulum swing freely and observe the final resting point.

4. The students discuss their observations, focusing on the fact that the pendulum always comes back to the same resting point or the center, further solidifying the concept that gravity pulls everything towards the center of mass. They also infer that when the pendulum is pulled and released, it pushes back towards the center, and if given enough time with no external interruptions, it would eventually stop at the exact center point.

5. They compare the results of both activities, enhancing their understanding of gravitational force and its direction.

Activity 3: Discussion and Real-World Examples

1. Finally, the teacher encourages a class-wide discussion. The students are asked to share real-world examples where the concept of gravity pulling everything towards its center of mass is applicable. This could include phenomena like rain falling from the sky, the flow of rivers, how we stay grounded on the earth regardless of which part of the world we stand in, etc.

2. The teacher emphasizes how their understanding of the gravitational force direction can be applied to appreciate and explain various phenomena in their daily lives. This is an important step towards reinforcing the abstract concept of gravity into their concrete understanding.

Feedback (5 - 10 minutes)

1. The teacher initiates a group discussion where each group shares their conclusions from the two activities. The students explain their observations and how they related them to the concept of gravitational force and its direction.

   1.1. The teacher encourages the students to discuss their findings, fostering a vibrant and collaborative learning environment. The teacher emphasizes the importance of respecting differing viewpoints and promotes a healthy exchange of ideas.

   1.2. The teacher guides the conversation towards the understanding that gravity pulls everything towards the center of mass. The teacher ensures that this concept is clearly understood by all groups and students.

2. After the group discussion, the teacher assesses what was learned from the activities.

   2.1. The teacher briefly recaps the purpose of the activities and then asks the students to share how these activities connect with the theory of gravitational force direction.

   2.2. The teacher listens to the students' responses and assesses their understanding of the concept. This is done by observing their ability to articulate their thoughts, their use of scientific vocabulary, and their ability to make connections between the hands-on experiences and the theoretical concept.

   2.3. The teacher provides constructive feedback on their responses, clarifying any misconceptions or misunderstandings and reinforcing the correct understanding of the concept.

3. Following the assessment, the teacher asks the students to reflect on their learning.

   3.1. The teacher proposes reflective questions such as: - What was the most important concept learned today? - Which questions have not yet been answered? - How has your understanding of gravitational force and its direction changed after today's lesson? - Can you think of other real-world examples where the concept of gravitational force direction is applicable?

   3.2. The students take a moment to think about these questions and then share their thoughts. This reflection helps the students consolidate their learning and identify any gaps in their understanding.

4. Finally, the teacher concludes the lesson by summarizing the key points and praising the students for their active participation and valuable contributions to the class discussion. The teacher reminds the students that understanding the concept of gravitational force direction is fundamental in physics and applies to many real-world scenarios.

By the end of this feedback stage, the students should have a clear understanding of gravitational force and its direction towards the center of mass. They should be able to articulate this concept, draw connections between their hands-on experiences and the theoretical concept, and apply their understanding to real-world examples.

Conclusion (5 - 10 minutes)

1. The teacher begins the concluding phase by summarizing the key points of the lesson. They remind the students that gravitational force always pulls objects towards the center of mass, which in most of their experiences is the center of the Earth. This key principle was demonstrated through hands-on activities involving juggling balls and pendulums.

2. They highlight the connection between theory and practice made during the lesson. The teacher explains that through the practical demonstration of dropping and throwing balls, and observing pendulum behavior, the students were able to visibly see and understand the concept of gravitational force and its direction. They stress that these activities were not merely games, but practical applications of the theoretical concept they learned.

3. The teacher suggests additional materials for the students to further their understanding of the topic. They recommend educational videos and animations on gravitational force and its direction, and children-friendly books on the subject, such as "Gravity is a Mystery" by Franklyn M. Branley and "The Falling Girl: Chronicles of the Closed World, Book 1" by D.D. Marks. They also recommend online physics games and simulations that allow students to explore gravity in a fun, interactive way.

4. The teacher concludes by explaining the importance of understanding gravitational force and its direction for everyday life. They illustrate this importance with examples such as understanding why we don't float off the ground, why we need to exert force to lift objects, why it is easier to go downhill than uphill, and why structures like buildings and bridges need to be built to withstand the pull of gravity.

5. Lastly, the teacher encourages the students to keep observing and thinking about the world around them, stressing that every observation can lead to understanding a new concept, just like Sir Isaac Newton's observation of the falling apple led to the discovery of gravity. They conclude the lesson by reminding the students that the knowledge they gained today is a stepping stone for understanding more complex concepts in physics in the future.