On Friday (29/08/2014), students of grade 4 elementary school SAIMS conduct experiments on the propagation of sound energy. In this experiment, students utilize used goods as a learning medium. Bottle and glass of mineral water in containers that are not used in such a way that it becomes used to learn the media. There were brought from the house, there is also the use of bottles that exist in the class-which will be collected at Waste Bank school.

Experiment 3 kinds. They will examine the propagation of sound through solids, air, and liquid. In the first experiment, the glass container perforated bottom. Yarn mattress then inserted and fastened so as not to be separated. At the other end of the string are also treated the same so that the glass on one end can be used to talk and the other end to hear. Students find that the sound will be heard if the thread in a tense situation. If not, the sound will not be heard at all.

Students are then directed to make a series of bottles were spliced ​​with masking tape. With their compact divides the task cut out with a cutter and taped. Both ends of the same functions as the first experiment. The air inside the bottle into the sound propagation medium issued. This happens as the activities of talking face without any barrier. Various experiments later performed, such as by closing the bottle on both sides and also incorporate the fabric into the bottle.

In the last experiment, the student reads electronic toys wrapped in plastic. They then put it into a plastic bucket filled with water. Students can feel the vibration in the hand dipping a toy, but her voice became weaker or even no sound. At the end of the session, students record the results of tests on the worksheet sheet, with the conclusion that the sound can propagate through an intermediary.