Contextualization

Lenses are an object used in many applications in our daily lives. They are used in the manufacture of eyeglasses, microscopes, telescopes, cameras, among other equipment, thus allowing us to see the world in a clearer and more precise way. Lenses are capable of diverting the path of light, bending it, so that it can focus or spread the light rays at a single point or in several directions.

There are two types of lenses: Converging lenses and diverging lenses. Converging lenses are those that converge parallel light rays to a single point, called the focus. They are thicker in the center than at the edges. Diverging lenses, on the other hand, do the opposite, that is, they spread parallel light rays through several points. They are thinner in the center and thicker at the edges.

Understanding how lenses work is fundamental to engineering, biology, astronomy, photography, ophthalmology, among other areas. In engineering, for example, lenses are used in the construction of measuring equipment, such as the theodolite, used in topography. In biology and medicine, microscopes, which contain lenses, allow the visualization of microorganisms. In ophthalmology, lenses are used both to correct vision problems and to visualize structures of the eye in the fundus examination.

The purpose of this project is to study the types of lenses, their applications in the real world, and their physical properties, especially with regard to the refraction of light. To this end, you will perform a series of practical and theoretical activities that will help deepen your knowledge on this subject.

You can search for additional information and deepen your studies in the following resources:

• Book "Fundamentals of Physics: Optics and Modern Physics", by Halliday, Resnick and Walker.
• Brasil Escola website, in the Physics section, available at https://brasilescola.uol.com.br/fisica/lentes.htm.
• Youtube channel "Ciência em Ação" (Science in Action), where you can find several videos on the subject, available at https://www.youtube.com/c/cienciaemacao/featured.
• Website "Só Física" (Only Physics), in the optics section, available at https://www.sofisica.com.br/conteudos/Optica/Lentes/.

Practical Activity: "Exploring the World of Lenses"

Project Objective

The objective of the project is to understand in a practical and theoretical way the concepts about lenses, mainly converging and diverging lenses, through the construction of their own lenses and the observation of their characteristics and effects.

Project Description

The students will form groups of 3 to 5 members and will build two simple lenses, one converging and one diverging, using low-cost materials. With these lenses, they will perform a series of experiments and observations to better understand the principles and properties of lenses and the refraction of light.

Materials Needed

1. Two transparent plastic (or glass) cups
2. Water
3. Graph paper
4. Pencil and pen
5. Ruler
6. Flashlight
7. Balloon
8. Scissors

Project Step by Step

1. Fill one cup with water to the brim. This will be your converging lens.
2. Cut the balloon in half and place it over the other cup. Then, slightly sink the middle of the balloon with your finger and fill it with water. This will be your diverging lens.
3. Using graph paper, draw two parallel lines to represent light rays.
4. Place the lens (cup with water) on the line and illuminate it with the flashlight. Observe how the light behaves as it passes through the converging lens and the diverging lens.
5. Record your observations and try to connect with what you have learned in theory.

Project Deliverables and Document Writing

After the completion of the practical part, each group must prepare a report that follows the structure below:

1. Introduction: The group should introduce the concept of lenses, the importance of these objects in our daily lives and their applicability in the real world. You should also mention the objective of the project.
2. Development: Detailing the theory behind converging and diverging lenses. Detailed explanation of the execution of the experiments, including the step-by-step and the explanation of the method used to construct the lenses and to observe the light rays passing through them. In addition, presentation and discussion of the results obtained and the conclusions drawn from the experiments performed.
3. Conclusion: Recapitulation of the key points, focusing on what was learned throughout the project, the conclusions drawn, and the practical application of the knowledge of lenses in life and society.
4. Bibliography: All resources used to prepare the project should be listed here.

Remember, the idea is for the report to complement the practical experience, so relate to it actively when writing the paper. For example, when explaining the theory of lenses, refer to what you observed in the experiments conducted. Be creative, critical, and detailed. Teamwork, communication, time management, problem solving, and creative thinking are essential skills that will be worked on during this project.