The 8th graders are continuing their exploration on different types of energies (Potential Energy, Kinetic Energy, Elastic Potential Energy, Gravitational Potential Energy, Thermal Energy, Sound Energy and much more!) and how these energy types either transfer or transform in systems. Students learned that Energy Transfer is when the energy is moved from one part of a system (or object) to another but stays as the same type of energy, and that Energy Transformation is when a specific type of energy is converted into another type of energy (i.e. Kinetic Energy -> Thermal Energy).

In our rollback can lab, students constructed their own versions of a can design, that when rolled forward, the can will return back to its starting position almost like a boomerang. In order for the students to build their experiments they were given the following materials: tape, coffee can, 2 paper clips, a washer(s) or screw-nut, a rubber band and string. Each student built their own rollback can with the guidance of a lab procedure as well as their teacher. Once students were done building, they put their designs to the test! If it was successful, when the student rolls the can forward, the weight inside of the can tied to the rubber-band holds the center of the rubber-band still however, the rubber-band on either side of the weight will twist as the can rolls. As the rubber-band twists it is gaining Elastic Potential Energy that was converted from Kinetic Energy (energy associated with movement). Once all of the Kinetic Energy has been transformed into Elastic Potential Energy, the can stops moving forward but then proceeds to move backwards! The reason the can is now rolling backwards is because the built up Elastic Potential Energy in the rubber-band is now being released (as the rubber-band unwinds) and transformed back into Kinetic Energy, allowing the can to roll back to its original starting position.

By the end of the lab, students had such a great time building their designs and they even had friendly competition to see whose design worked the best! Students gained a much clearer understanding of energies in systems and how they interact.