Lesson Plan | Active Learning | Electricity: Electric Power

Assumptions: This Active Lesson Plan assumes: a 100-minute class, prior student study with both the Book and the start of Project development, and that only one activity (among the three suggested) will be chosen to be conducted during the class, as each activity is designed to take up a significant portion of the available time.

Objectives

Duration: (5 - 10 minutes)

The objectives stage is crucial to guide both the teacher and the students on what will be focused on during the class. By clearly establishing the objectives, the groundwork is laid for understanding and applying the concepts of electrical power in both practical and theoretical ways. This provides a solid foundation for students to effectively apply the knowledge gained with a full understanding of the subject.

Main Objectives:

1. Enable students to calculate the power generated by the Joule effect in resistors or circuits, exploring the relationship between power, current, and resistance.

2. Develop the ability to solve practical problems involving electrical power calculations, such as determining the time needed to heat a specific amount of water in a resistor.

Side Objectives:

1. Encourage reflection on energy efficiency and the importance of energy conservation in everyday life.

Introduction

Duration: (15 - 20 minutes)

The Introduction stage aims to engage students with the content they studied previously by using problem situations that encourage the direct application of theoretical knowledge. Additionally, by contextualizing the importance of electrical power in daily life, students are motivated to understand the relevance of what they are learning and how this knowledge can be applied in their lives and future professional decisions.

Problem-Based Situations

1. Imagine a household that uses an electric shower to heat water. The shower operates at a power of 5500 watts and is used for 30 minutes a day. Knowing that the cost of electricity is R$ 0.40 per kWh, how do you calculate the monthly operating cost of the shower?

2. Consider a circuit with a 60-watt incandescent bulb connected to a 120-volt source. What is the current flowing through the bulb and what is the electrical resistance of the bulb?

Contextualization

Electrical power is a fundamental concept that permeates various situations in our daily lives, from the operation of household appliances to large-scale energy generation. Discussing the relevance of electrical power through practical examples, such as calculating the operating cost of devices and energy efficiency, not only makes the theory more tangible but also highlights the importance of studying electricity for the conscious use of resources and household economy.

Development

Duration: (70 - 75 minutes)

The Development stage is designed for students to practically and interactively apply the concepts of electrical power that they studied previously. By working in groups, they reinforce theoretical knowledge through solving real problems, while also developing collaboration and communication skills. Each activity is designed to be challenging and engaging, ensuring that students are fully immersed in learning during the class.

Activity Suggestions

It is recommended to carry out only one of the suggested activities

Activity 1 - Power Master Challenge

> Duration: (60 - 70 minutes)

- Objective: Apply theoretical knowledge of electrical power to solve a practical engineering problem, promoting teamwork and creativity.

- Description: In this activity, students are divided into groups of up to five people and challenged to design a heating system for a small pool using electric resistors. They must consider factors such as energy efficiency, heating time, and safety. Each group receives a list of available materials and a limited budget.

- Instructions:

• Divide the class into groups of up to five students.

• Present the problem situation: to heat a pool measuring 3m x 2m x 1.5m in depth from 20°C to 28°C within 24 hours.

• Provide a list of materials that includes electric resistors, cables, thermostats, and thermal insulation, in addition to a fictional budget.

• Each group must calculate the required power, cost, and environmental impact of the proposed system.

• Prepare a presentation to defend the project, explaining the choices made and how energy efficiency was considered.

Activity 2 - Energy Efficiency Scientists

> Duration: (60 - 70 minutes)

- Objective: Develop analytical and energy management skills by using concepts of electrical power to make informed decisions about energy efficiency.

- Description: Students, in groups, take on the role of energy consultants for a company seeking to reduce its operational costs. They should analyze the energy consumption of different equipment, such as light bulbs, computers, and air conditioning, and propose solutions to increase energy efficiency.

- Instructions:

• Form groups of up to five students.

• Distribute energy consumption data for different equipment and the cost of electricity.

• Students should calculate the power and operating cost of each piece of equipment.

• Propose solutions to reduce energy consumption, such as replacing with more efficient equipment.

• Prepare a report with analyses and recommendations to present to the fictional company.

Activity 3 - Circuit Builders

> Duration: (60 - 70 minutes)

- Objective: Understand in practice how electrical power is calculated and how different components affect the functioning of a circuit.

- Description: This practical activity involves building simple circuits in which students must calculate and adjust the power to light a bulb. They will explore different resistances and measure the current to check if the power is correct.

- Instructions:

• Divide the class into groups of up to five students.

• Distribute kits with basic electronic components, including resistors, wires, and a bulb.

• Instruct students to design a circuit that lights the bulb and calculate the necessary power.

• Measure the current in the circuit and check if the bulb is operating correctly.

• Discuss the results and possible sources of error in the calculation or circuit assembly.

Feedback

Duration: (15 - 20 minutes)

This stage of the lesson plan is essential to consolidate students' learning, allowing them to reflect on the practical activities carried out and discuss their experiences. Through this feedback session, students have the opportunity to verbalize and confront their ideas, promoting a deeper understanding of the content. Additionally, by hearing the experiences of their peers, students can gain new perspectives and insights, further enriching their learning.

Group Discussion

To start the group discussion, the teacher should ask each group to briefly share the project they developed, highlighting the main challenges encountered and the innovative solutions proposed. Then, the teacher can guide the discussion to explore the different approaches used by the groups and how these approaches reflect an understanding of the concept of electrical power. This moment is crucial for students to learn from each other and see the practical applications of the discussed concepts.

Key Questions

1. What were the biggest difficulties you encountered when calculating the power required to heat the pool?

2. How was energy efficiency considered in your project and what measures were taken to maximize efficiency?

3. Were there any surprises in the results obtained regarding the energy consumption of the analyzed equipment?

Conclusion

Duration: (5 - 10 minutes)

The purpose of this Conclusion stage is to ensure that students have a clear and consolidated understanding of the concepts of electrical power, as well as to recognize the applicability of these concepts in real-world situations. The summary and the bridge between theory and practice help reinforce learning, while the discussion of practical applications encourages students to see the value of what they have learned in their daily lives and future careers.

Summary

In the Conclusion stage, the teacher should provide a comprehensive summary of the concepts studied, reinforcing the definition of electrical power, the relationship between current, voltage, and resistance, and how these factors apply in different practical contexts. It is important to recap the calculations made by students in the activities for heating the pool and energy efficiency, emphasizing the innovative solutions proposed by the groups.

Theory Connection

During the class, theory was connected with practice through challenging and contextualized activities, such as the pool heating project and the energy efficiency analysis. These activities allowed students to directly apply the concepts of electrical power, consolidating theoretical understanding through solving real problems, which reinforces the importance of theory in understanding and solving practical situations.

Closing

To conclude, the teacher should highlight the importance of studying electrical power in everyday life, emphasizing how the knowledge acquired can be applied for the efficient use of energy resources and in making sustainable decisions. Furthermore, it is crucial to emphasize the relevance of energy efficiency in a global context of environmental concern and resource scarcity, encouraging students to consider these aspects in their future professional and personal practices.