A Backyard Science Visit
During a supervised science visit, Ms. Chen's class investigated energy around her backyard sandbox. They used a dry board beside the sandbox for equipment. Students recorded what changed at a place away from an energy source. They completed one test at a time so the equipment from one test would not affect another.
First, the class connected a low-voltage battery, wires, a switch, and a small buzzer. The battery was one meter from the buzzer. Imani listened from the other side of the sandbox. With the switch open, she heard no buzz. Closing the switch made the buzzer sound. Opening it stopped the sound. They repeated this three times without moving the battery, buzzer, or listener. The buzzer setting stayed the same.
Next, students stood a white card in shade inside the sandbox. A small mirror rested at a sunny edge. An adult adjusted the mirror until a bright patch appeared on the card one meter away. Turning the mirror face down removed the patch. Returning it to its earlier position brought the patch back. The card stayed in shade.
With the mirror aimed at the card, students placed cardboard across the path between them. The bright patch disappeared. They then moved the cardboard behind the card, away from that path. The bright patch returned. They kept the mirror and card in the same positions.
Finally, students put equal amounts of dry sand into three identical thin plastic trays. Each sample began at 26°C. An adult supplied two identical sealed cold packs kept near 8°C. One tray rested directly on a pack. Another rested on a foam sheet placed on the second pack. The third tray rested on the board without a pack.
All three trays stayed in shade for eight minutes. The air remained near 26°C. Students kept the sand depth, tray type, and measuring time the same. They measured the sand at the same depth in each tray. The packs stayed sealed, so no pack liquid entered the sand. The graph shows the final temperatures.