Contextualization

Physics is a science that studies the laws of nature. Among the various concepts studied in Physics, we highlight mechanical energy, which is present in our daily lives and is essential for many technical, scientific, and industrial applications. Mechanical energy is defined as the sum of two other forms of energy: kinetic energy, associated with the movement of a body, and potential energy, related to the position or configuration of a body.

Mechanical energy is a very important concept in Physics because it allows the performance of work, that is, it is the cause of a change in the movement of a body. Furthermore, mechanical energy is conserved in an isolated system, that is, the sum of the kinetic and potential energies of a system does not change over time unless some external force acts on that system. These are some of the fundamental properties of mechanical energy that will be explored in this project.

Mechanical energy is present in various situations in our daily lives. When we push a shopping cart, we are applying a force that modifies the kinetic energy of the cart, causing it to move. When we lift an object, we are increasing its potential energy due to the action of gravity. In industry, mechanical energy is used to move machines and equipment. In the generation of electrical energy, mechanical energy is converted into electrical energy. Therefore, the study of mechanical energy is important not only for the understanding of physical phenomena but also for technology and society.

Practical Activity: "The Roller Coaster of Mechanical Energy"

Project Objective

The objective of this project is to understand the principles of conservation of mechanical energy through the construction of a miniature roller coaster using household materials.

Project Description

Students, organized in groups of 3 to 5, will build a circuit, similar to a roller coaster, in which a small ball or a cart can move due to gravity. Students should plan and build their circuit in a way that highlights the transformations of potential energy into kinetic energy and vice versa along the path.

Next, students will take measurements of time and distance at different points in the circuit, and based on this data, using the laws of physics, they will calculate the potential, kinetic, and mechanical energies of the system at each point.

Required Materials

1. PVC or cardboard tubes
2. Adhesive tape or glue
3. Ruler or measuring tape
4. Small ball or mini cart
5. Stopwatch (can be on the phone)

Step by Step

1. Gather all the necessary materials for building the circuit.
2. Plan the roller coaster. Remember to add hills and valleys to demonstrate energy conversion.
3. Build the roller coaster using the tubes and adhesive tape.
4. Place the ball at the top of the roller coaster and let it descend propelled by gravity. Make adjustments to the circuit if necessary.
5. Mark different points on the roller coaster and measure the time it takes for the ball to pass through each of these points.
6. Using the laws of physics, calculate the mechanical, kinetic, and potential energies at each point.

Project Deliverables

At the end of the practical project execution, students will write a report that collects and presents the results of their experiment, namely:

1. Introduction: Describing the experiment's objective, the importance of mechanical energy, and its real-world applications.
2. Development: Should include the project's stages, explaining the theoretical principles of the conversion between potential and kinetic energies and the conservation of mechanical energy. It should also contain the description of the built roller coaster circuit, along with photographs or drawings, as well as the methodology used for data collection and processing.
3. Results and Discussion: Present the measurement results and energy calculations at each point, as well as graphs illustrating the transformation of potential and kinetic energies along the path and the conservation of mechanical energy. Results should be discussed in light of the theory, identify possible sources of error, and suggest improvements in project execution.
4. Conclusions: Students should draw a conclusion that coordinates the most relevant points of the project, highlighting what they learned from it and expressing their reflections on the importance of mechanical energy in daily life.
5. Bibliography: List all sources consulted during the work.