Instruction Guide: EV3 - Potential Energy

Students will use the programming skills they learned from “Move Straight” to design a robot that maximizes its efficiency, using the least amount of power possible by increasing its potential energy.

Students should use the Potential Energy Efficiency Engineering Log assignment sheet to complete this project.

When to Use This Science/Engineering Project
This assignment is best used as a way to apply knowledge already learned about potential energy, kinetic energy, mass, gravity, and velocity. Have students refer to specific texts, notes, or assignments they have already completed to help them with the research section of the Engineering Log.

Problem and Research
Each pair of students will design and build a robot that uses potential and kinetic energy to do a job using the least amount of power possible. To simplify things, this engineering project focuses on the potential energy equation involving height. The robot must have an arm or extension that drops from a height. For example, the robot might cut a banana with an arm that falls from a height. Have each pair choose a different job so students can see several different uses for the same robot.

After students choose a job for their root to do, they must get the job approved by you and explain how the job utilizes potential energy. Once their job is approved, they must research definitions of key vocabulary terms used and analyze the equations for potential and kinetic energy.

Students will draw and label their prototype. They need to explain how they utilize the most height and mass possible to increase their potential energy. They also need to decide on the amount of power they will program their robot to use when they do their initial test. Recommend that they use a high number to start with so they can optimize their robot for a lower amount of power during their redesign. They also need to write what outcome they are looking for if their robot performs its task and give each partner a role. Tell students that each student is in charge of building and programming, so they need to decide what each partner is in charge of building and programming specifically. For example, partner A is in charge of building the arm and partner b is in charge of building the base.

After getting their prototype approved by you, they can build their robot.

After testing their robot, students will optimize the robot to make it more efficient. Students will need to measure the height, mass and velocity of the part of the robot that is doing work. For example, if the robot is cutting a banana with an arm. Students need to measure the height of the arm from the point where it starts to the point where it ends. The arm needs to be measured in meters because the equation for potential energy is calculated in meters. The students will also measure the mass of the arm in grams on a scale. The student should not measure the mass of the entire robot, because there are parts of the robot that are not doing work (usually the brick is not doing work).

After students finish optimizing their robot, they will draw their final design and graph the amount of power each robot needed to do its job. If students calculated their potential energy in their redesign, they can graph this number as well.

Argue from Evidence and Communicate Information
Students should share their robots with the class when they finish. After each group has shared, lead a class discussion about why certain robots were more efficient than others. Consider how each group used potential and kinetic energy to increase their efficiency. Discuss how potential energy is used in our everyday lives to increase efficiency (elevators, car coasting down a hill, garage door, etc.).