Context

Theoretical Introduction

Friction is a force that acts whenever two objects come into contact. It was Isaac Newton who first dealt with the concept of friction, establishing two variations: static friction and dynamic friction.

Static friction occurs when the bodies are not in relative motion, that is, when the object is at rest. It is responsible for providing the necessary adhesion between the surfaces in contact to prevent their initial movement, and it is this type of friction that we will address in this project.

However, it is important to remember that friction is not a property only of solid objects. It is also experienced in liquid and gaseous mediums, often called air resistance or fluid resistance. The difference is that friction in fluids does not have two distinct states (static and dynamic) as in the case of solid surfaces.

Theme Contextualization

Perhaps you have never thought about it, but friction is present in almost all of our daily activities. When we walk or run, the friction between our feet and the ground allows us to move forward. When we write with a pencil, the friction between the pencil and the paper allows the graphite to stay on the paper. When we drive, the friction between the tires and the road allows the car to move, brake, and change direction.

Consequently, the lack of friction can cause serious problems. Imagine, for example, if suddenly there was no friction between the car tires and the road. It would not be possible to control the vehicle, which could lead to numerous traffic accidents. Furthermore, if there was no friction between our feet and the ground, it would be impossible to walk without slipping.

To better understand and delve into the subject, here are some suggestions for materials:

• Book: "The Feynman Lectures on Physics, Vol. I", chapter 12 (Richard Feynman) - Available in various libraries and bookstores.
• Video: "Friction Force and Inclined Plane", available on Professor Boaro's YouTube channel.
• Website: Brazil School - Static and Dynamic Friction.

Practical Activity

Activity Title:

"Static Friction: Building Knowledge"

Project Objective:

To investigate, through simple experiments, how static friction force acts in preventing the movement of objects and how it can be calculated.

Detailed Project Description:

In this activity, students will work in groups of 3 to 5 to carry out a practical experiment involving static friction force. The central idea will be to observe and measure the force required to make different surfaces slide over each other. Through trial and error, students will experiment with how different material combinations alter static friction force.

Required Materials:

• Various materials with different textures (wood, glass, metal, plastic, rubber, paper, fabric, etc.)
• Digital scale
• An object that can be easily measured on the scale (e.g., a heavy book)
• Tape measure or ruler
• Notes and pen to record observations
• Calculator

Detailed Step-by-Step for Activity Execution:

1. Organize: Each group should choose a leader, who will be responsible for coordinating the experiment and ensuring that everyone participates actively.

2. Preparation: Organize the surfaces of different materials on the workbench.

3. Weighing: Weigh the book (or chosen object) on the scale and record its weight.

4. Experiment: One at a time, place the book (or chosen object) on one of the surfaces. Start sliding the surface gently under the object until the object starts to move. Repeat the test with all available surfaces.

5. Recording: Record your observations in detail. Which surface required more force to move the object? Which required less?

6. Analysis: Based on your observations, students should discuss and try to understand what happened. Why do some surfaces require more force to initiate movement than others?

7. Conclusion: Students should conclude the experiment and formulate their own theories about why different surfaces exhibit different static friction forces.

Project Deliverables:

At the end of the project, each group of students must produce a written report with the following parts:

1. Introduction: In this section, students must explain what static friction force is, why it is important, and what they expect to learn from the experiment. Include the project's objective.

2. Development: Here, students must detail the experiment conducted. Include the materials used, the surfaces tested, the data collected during the experiment, and the method of conducting the experiment. You should also include the theory behind static friction, the methodology used, and present observations and discussions on the results obtained.

3. Conclusion: In this part, students must review the main points of the experiment, discuss what they learned, and express their conclusions about the project. What were the most surprising findings? How does this relate to the application of static friction in the real world?

4. Bibliography: Here, students must include all sources from which they obtained information to carry out the project. Each cited source must be properly referenced.

This project is to be completed in one week, and each group member should expect to spend between two to four hours working on it. Remember: this project is about collaboration and mutual learning, so take the opportunity to learn together!