A Rolling Ball and a Plant Saucer
The school garden club uses a long, level potting bench for a motion investigation. Priya finds an empty plastic saucer, the shallow dish that usually sits under a plant pot. The club places the saucer on a clear part of the bench. A smooth wooden ball rolls into its side. The saucer slides forward without tipping.
The club wants to investigate how the ball's speed is related to its energy. Energy cannot be seen directly, so the students observe what happens when the moving ball hits something. They decide to measure how far the saucer slides after each bump. They also record how fast the ball moves just before it reaches the saucer.
An adult helps record the motion with a camera beside a measuring strip. In the slow run, the ball travels 20 centimeters in one second just before the bump. In the middle run, it travels 40 centimeters in one second. In the fast run, it travels 60 centimeters in one second. Traveling farther in the same amount of time means moving faster. The students use gentle pushes to produce the different speeds.
For every run, the club uses the same ball and the same empty saucer. Students put the saucer back on its starting mark and keep the bench surface dry and clear. They measure from the saucer's starting position to its resting position. A folded towel near the end catches the equipment if needed. The graph shows the saucer's sliding distance in the first run at each speed. The club saves these results before repeating the tests.