Lesson Plan | Traditional Methodology | Work: Graphics

Objectives

Duration: 10 to 15 minutes

The purpose of this stage is to provide students with a clear understanding of the lesson objectives and the skills that will be developed. By defining these objectives, students will understand the importance of using graphs to calculate the work of a force and how this technique will be applied during the lesson.

Main Objectives

1. Explain the relationship between work, force, and displacement.

2. Demonstrate how the area under the force versus displacement graph represents the work done.

3. Teach how to calculate work using force graphs by displacement.

Introduction

Duration: 10 to 15 minutes

The purpose of this stage is to provide an engaging and contextualized introduction to the lesson's theme, sparking students' interest and curiosity. By connecting theory with practical examples and curiosities, students will feel more motivated to understand how work is calculated and represented graphically, preparing them to absorb the more detailed concepts that will be presented later.

Context

Start by explaining that in Physics, the concept of work is fundamental to understanding how energy is transferred between systems. It is directly related to the applied force and the displacement caused by that force. Use everyday examples, such as pushing a shopping cart or lifting a heavy box, to illustrate how the application of a resultant force involves work. Emphasize that we often use graphs to represent this relationship in a visual and clear manner, facilitating the calculation of work done.

Curiosities

Did you know that the concept of work and energy is widely used in engineering to design efficient machines and structures? For example, engineers calculate the work needed to move elevators, operate cranes, and even design racetracks where cars need less force to reach high speeds. This shows how Physics is present in many aspects of our daily lives, even when we don’t notice.

Development

Duration: 45 to 55 minutes

The purpose of this stage is to deepen students' knowledge of the concept of work in Physics and how it can be calculated using force versus displacement graphs. By explaining each topic in detail and providing practical examples, students will be able to visualize and better understand the application of theoretical concepts. The proposed questions will serve to consolidate learning, allowing students to practice calculations and graph interpretation under the teacher's guidance.

Covered Topics

1. Definition of Work in Physics: Explain that work is defined as the force applied to an object times the displacement of that object in the direction of the force. The basic formula is W = F * d * cos(θ), where W is work, F is force, d is displacement, and θ is the angle between the force and the displacement. 2. Force vs. Displacement Graphs: Detail how force versus displacement graphs can be used to calculate work. Explain that the area under the curve in a force versus displacement graph represents the work done. Use simple examples with constant and variable forces. 3. Calculating the Area Under the Curve: Demonstrate how to calculate the area under the curve in different types of graphs. Use rectangles, triangles, and other simple geometric shapes to calculate the area and, consequently, the work. Present practical examples and guide students in problem-solving. 4. Practical Examples and Applications: Provide practical examples of how work is calculated in real-life situations, such as pushing an object on a flat surface or lifting an object against gravity. Explain how these situations can be graphically represented and how to calculate the work done in each case.

Classroom Questions

1. An object is pushed with a constant force of 10 N over a distance of 5 meters. Draw the force versus displacement graph and calculate the work done. 2. A variable force is applied to an object, as represented in the graph below. Calculate the work done by the force over the displacement shown in the graph. 3. An object is lifted vertically with a force of 50 N over a distance of 2 meters. Draw the force versus displacement graph and determine the work done by the force.

Questions Discussion

Duration: 20 to 25 minutes

The purpose of this stage is to review and consolidate students' learning, ensuring they fully understand how to calculate work using force versus displacement graphs. The detailed discussion of the questions and student engagement through reflective questions help solidify knowledge and promote a deeper understanding of the concepts taught.

Discussion

• Explain that for the first question, drawing the constant force graph (10 N) versus displacement (5 m) results in a rectangle. The area of the rectangle (force * displacement) is 10 N * 5 m = 50 J, which is the work done.

• For the second question, emphasize that the variable force will require integrating the area under the curve of the graph. Break the graph down into simple geometric shapes, such as rectangles and triangles, and calculate the area of each. Add the areas to find the total work done.

• In the third question, draw the constant force graph (50 N) versus displacement (2 m), which also results in a rectangle. The area of the rectangle is 50 N * 2 m = 100 J, which is the work done.

Student Engagement

1. How can we use force versus displacement graphs to better understand the concept of work in different contexts? 2. What are the challenges of calculating work using graphs with variable forces, and how can we overcome them? 3. How can the understanding of work and energy be applied to practical situations in daily life, such as in sports or engineering? 4. Are there other ways to graphically represent the work done besides force versus displacement graphs?

Conclusion

Duration: 10 to 15 minutes

The purpose of this stage is to review and consolidate the main concepts presented in the lesson, ensuring that students understand the importance and application of work and force versus displacement graphs. This final summary helps solidify knowledge and connect theory to practice.

Summary

• Work is defined as the force applied to an object times the displacement of that object in the direction of the force, with the formula W = F * d * cos(θ).
• Force versus displacement graphs are used to calculate the work done, where the area under the curve represents the work.
• The area under the curve can be calculated using simple geometric shapes, such as rectangles and triangles, to determine the work in cases of constant and variable force.
• Practical examples, such as pushing objects or lifting weights, were used to illustrate the application of work concepts and force versus displacement graphs.

During the lesson, the theory about work and its formula was connected to practice through force versus displacement graphs. Practical examples and guided activities showed how to calculate work in real situations, reinforcing students' understanding of how physics is applied in everyday life and engineering.

Understanding work and its graphical representation is crucial in daily life. Engineers use these concepts to design efficient machines and structures, while in sports, understanding work and energy can help improve performance and athlete safety. These examples show how physics is present in many areas of our lives.