Contextualization

Theoretical Introduction

Physics is a science that studies the phenomena of nature, and within it we have Mechanics, which studies the movement of bodies and the forces acting on them. Within Mechanics, we have a branch called 'Statics', which is the study of Physics that deals with the conditions under which a body or system of bodies remains at rest or in uniform motion. In other words, it is the study of bodies that are not accelerating.

The term 'rigid body' is used to describe a body whose shape and size are fixed and do not change under the influence of external forces. That is, a rigid body does not deform when subjected to forces. In reality, there is no perfectly rigid body, but we use this model to simplify the study of many physical systems.

In the study of the statics of a rigid body, two concepts are fundamental: forces and moments. A force is an action that has the ability to change the speed or shape of a body. The moment of a force, also known as torque, is a measure of the ability of that force to rotate a body around a point or axis.

Importance and Contextualization

Statics is very important in everyday life and in various areas of science and engineering. It allows us to understand and predict when and why objects are stable or unstable. Bridges, buildings, cranes, bookshelves, and many other objects and structures we use every day were designed with the help of statics.

Every time you sit on a chair, lean on a table, carry a backpack, or even when you are standing, you are interacting with statics. The forces exerted by and against these objects must be balanced for them to remain at rest. And how can we describe and calculate these forces? With the concepts and laws of statics!

Activity: Simulation and Static Analysis of a Toothpick Bridge

Project Objective

The activity aims to apply statics concepts in the construction of a toothpick bridge, to analyze the materials' resistance and the principles of force distribution and equilibrium. The project aims to foster collaboration and teamwork, planning and executing a practical project, analyzing results, and communicating their findings.

Project Description

Each group of 3 to 5 students will be responsible for designing and building a toothpick bridge that will be able to support the greatest amount of weight possible. The bridge must be made exclusively of wooden toothpicks and white glue.

After construction, students will test the bridges by progressively adding more weight until the bridge collapses to determine the maximum load their structure can support.

Required Materials

• Wooden toothpicks (can be barbecue or popsicle sticks)
• White glue
• Various weights to test the bridge's resistance (such as books, cans of food, etc.)
• Scales to measure force
• Ruler or tape measure

Step by Step

1. Research and Planning: Before starting construction, students should research bridge structures, force and moment concepts, and equilibrium principles. This will help them plan the construction of their bridge. The plan should be sketched in a notebook, indicating the shape of the bridge, where the forces will be applied, and how they will ensure the bridge is in equilibrium.

2. Construction: Students then begin building their bridge based on the planned design. Care should be taken to ensure that all toothpicks are well glued and that the structure is as symmetrical as possible to ensure its balance.

3. Tests: After the bridge is completely dry, students should perform the resistance test, gradually applying more weight to the bridge and recording how much weight it can withstand before collapsing.

4. Analysis and Report: Based on the test results, students should analyze why the bridge collapsed where it did, how the forces were distributed, and what could have been done to strengthen the bridge. This analysis should be included in the project report.

Project Deliverables and Written Document

Students must deliver the constructed bridge, as well as a written report that should include:

1. Introduction: The student must contextualize the theme, its relevance and real-world application, as well as the objective of this project.
2. Development: Detailed explanation of the bridge's design and construction, description of the tests performed, and presentation of the results obtained. Students should discuss how forces and moments were considered and calculated during construction. Explain the selection and use of materials, tools, and techniques employed during the project.
3. Conclusions: Discussion on the bridge's performance, test results, and conclusions drawn about the project. Recap the main points, explain the lessons learned, and how statics concepts were applied in practice. Evaluate teamwork, challenges encountered, and how they were resolved.
4. Bibliography: Indicate the sources they relied on to work on the project such as books, web pages, videos, etc.

The work should last about a month, and it is expected that each student dedicates between 5 to 10 hours of work to the project.