Contextualization

The study of thermal transformations involves understanding many fascinating concepts that are part of the field of thermodynamics, one of the most important areas of physics. During this adventure, topics such as thermal expansion, calorimetry, state changes, and ideal gases will be explored, and these will serve as the foundation for understanding more complex concepts, such as the First Law of Thermodynamics (Conservation of Energy) and the Carnot Cycle.

Through these topics, it is possible to understand how heat influences the variation in the dimensions of a body, how systems transfer energy in the form of heat, and how it is possible to take advantage of this energy to promote the completion of work. These concepts will be applied in everyday situations such as the expansion of train tracks with heat, the cooling of a refrigerant, and the operation of combustion engines.

The application of these concepts is not limited to our daily lives. They are of utmost importance in many industries, making possible everything from the generation of electrical energy in thermoelectric and nuclear power plants to the development of more efficient automobile engines. Understanding them allows us not only to better understand the world around us, but also to contribute to the construction of more sustainable and efficient solutions for our society’s energy challenges.

For a better understanding of the concepts, I recommend reading the chapters on thermal transformations in the books "Physics for Scientists and Engineers" by Serway & Jewett and "Fundamentals of Physics" by Halliday & Resnick, available in the library. In addition, the website Brasil Escola presents an overview of the topic in an accessible and didactic way. The video lessons on the Felipe Betti Channel on YouTube are also an excellent tool for deepening your understanding of the concepts and seeing practical applications of these transformations.

Practical Activity

Activity Title: "Building a Stirling Engine"

Project Objective:

The objective of this project is to build a prototype of the Stirling Engine, which is a thermal machine that operates on the Stirling cycle, allowing for the practical exploration of the theoretical concepts of thermal transformations studied in the classroom.

Detailed Description of the Project:

Each group, made up of 3–5 students, will be responsible for:

1. Studying and understanding the theoretical principles of the operation of the Stirling Engine and its thermodynamic cycle.

2. Gathering the necessary materials to build the engine.

3. Building the prototype of the Stirling Engine.

4. Conducting tests to verify the operation of the engine, interpreting and discussing the results obtained.

5. Writing a complete report on the project.

Required Materials:

The following will be required to build the engine:

• 2 empty soda cans
• 1 party balloon
• 1 straw (can be metal, paper, or plastic)
• Malleable copper wire
• Modeling clay
• 2 old CDs
• Tea light candles (can be found in camping supply stores)
• Tools: scissors, box cutter, pliers, hot glue

Detailed Step-by-Step Instructions for Completing the Activity:

1. Study the operation of the Stirling Engine: The group must research how the Stirling Engine works. It is recommended to read scientific articles, physics books, and watch explanatory videos on the topic.

2. Design and planning of the engine: Based on the studies, the students must draw and plan how they will build the engine.

3. Acquisition of materials: The students must gather all the materials needed to build the engine. It is very important that all the materials are available before beginning construction, to avoid interruptions.

4. Construction of the engine: Using the tools and materials gathered, the students must build the engine according to the plans they made. It is recommended that the students be careful when handling the tools to avoid accidents.

5. Tests and analysis of the results: After building the engine, the students must conduct tests to verify how it works. During the tests, the students must observe and record the variations in the air’s volume, pressure, and temperature in the engine.

6. Project report: Finally, the students must write a detailed report on the project, containing an introduction, development (with theory, description of the activity, methodology, and presentation and discussion of the results), conclusions, and bibliography used.

At the end of this project, the students will have a better understanding of thermal transformations and will develop skills such as teamwork, time management, creative thinking, proactivity, communication, and problem solving. In addition, the students will have the opportunity to get hands-on experience by building a prototype of a thermal machine, which is one of the practical applications of the physics studied.