Introduction

Elastic Force is a fundamental concept in physics and belongs to the category of conservative forces. It is closely related to Hooke's Law, a principle that states, "The force a spring exerts is directly proportional to the deformation it undergoes, and always has the opposite direction."

In the words of Sir Isaac Newton, "For every action, there is an equal and opposite reaction." Elastic force is the perfect highlight of this principle, where the spring or any other elastic body tries to return to its original state after being deformed. This force is given by the formula F = -kx, where F is the elastic force, k is the elastic constant of the body, and x is the deformation suffered by the body.

The work of Elastic Force is the energy transferred to deform a spring or any other elastic body. The work of a force is defined as the product of the force by the distance the object moves while the force is applied. In the case of elastic force, the work done is used to deform the body.

Contextualization

Elastic force is not just a theoretical concept, but it has many practical applications that are present in our daily lives. For example, consider a car's shock absorber. It uses elastic force to absorb the impacts of the terrain and prevent them from being transferred to the vehicle's chassis, making the ride more comfortable. Other examples include children's toys, stringed musical instruments, and the suspension system of a bridge.

Furthermore, elastic force is highly relevant in engineering and materials science. For instance, imagine an engineer designing a new bridge. They need to understand how elastic force works in order to design the bridge's suspension. Or for a materials scientist, knowing how materials respond to elastic forces can help create new materials with specific properties.

The work of elastic force is a clear example of how physics can be present in our daily lives, and how complex problems can be simplified and solved using basic principles.

Practical Activity

Activity Title: "Construction and Analysis of a Rubber Band Launcher"

Project Objective:

This project aims to provide reflection and understanding of Hooke's Law and the work of elastic force, through the construction and analysis of a playful mechanism: a rubber band launcher. Teamwork will be essential for the project's completion, and it is expected that students will develop not only technical skills in physics but also socio-emotional skills such as time management, communication, problem-solving, creative thinking, and proactivity.

Project Description:

Groups will consist of 3 to 5 students and will be tasked with building a rubber band launcher from common materials and then analyzing the operation of this launcher from the perspective of elastic force and Hooke's Law. They should explore how the distance of the rubber band launch is related to the elastic constant of the rubber band and the force applied to stretch it.

Students should document the entire process, from construction, experimentation, data collection, and analysis. In the end, they should produce a report with their findings, analyses, and conclusions.

Required Materials:

• Rubber bands of different types and sizes
• Rulers or tape measures
• Recyclable materials such as wood, cardboard, straws, adhesive tape, among others for the construction of the launcher

Step-by-Step for Activity Execution:

1. Brainstorm with your group and design your rubber band launcher. Your launcher should be able to launch rubber bands, and you should be able to adjust the force with which the rubber band is launched. Draw a diagram of your launcher and list all the parts needed to build it.

2. Build your rubber band launcher.

3. After building the launcher, test it with different types and sizes of rubber bands. Record the force applied to stretch the rubber band (which can be measured by the displacement of the rubber band in the launcher, for example) and the distance the rubber band was launched.

4. Collect the data and plot graphs relating the applied force, the elastic constant of the rubber band, and the launch distance.

5. Analyze the collected data and see how they relate to Hooke's Law and the work of elastic force. Do you notice any patterns? What can you conclude from your data?

Project Deliverables:

Students should submit a detailed report of the activity carried out in Markdown format with the following sections:

1. Introduction: Should contextualize the project, explaining what elastic force and Hooke's Law are, and why they are important. It should explicitly state the project's objective and how it can help understand these concepts.

2. Development: Should detail the entire procedure performed, from the construction of the launcher to data collection. Students should include images of the launcher and graphs produced from the collected data. Additionally, they should discuss the relationship between the applied force, the elastic constant of the rubber band, and the launch distance, and how this relates to Hooke's Law and the work of elastic force.

3. Conclusions: Students should reflect on the activity, discussing what they learned and how it enhances their understanding of elastic force. They should also mention any difficulties encountered during the project and how they were overcome.

4. Bibliography: Should indicate the sources consulted for the project.

Remember, the quality of the report is as important as the execution of the project itself. It should be well-written and formatted, with clear argumentation and appropriate use of graphs and images.