WASHOUGAL – Fourth-graders in Khrista McBride’s and Samantha Howard’s classes at Columbia River Gorge Elementary school applied science and engineering concepts as they built, tested and raced balloon-powered hovercraft. Balloons were connected to bottlecaps, which were glued onto CDs, creating a small gap for air to flow out, resulting in a small amount of lift to let the hovercrafts glide on hard surfaces.
Student tested their hovercrafts in several settings, and with different sized balloons. They measured the distance traveled, so they could analyze the resulting data and draw conclusions about what makes a successful hovercraft.
McBride said, “After the lesson, students reflected on the notes they gathered, and were surprised by the smaller balloons working better than larger balloons.” She described students discovering that “the smaller size allowed their hovercraft to move further and faster due to the continuous volume of airflow.”
Students also found that designing the hovercraft with the shiny side of the CD facing down worked better. Students found this through “their comparisons and discussion which led them to decide that the smooth side was the better one facing down. They learned that reducing friction made a difference.” Students also noticed differences between distance traveled due to the flooring, including that the hovercraft traveled less distance on a rug than hard materials.
By combining science and engineering processes together, students learned the practical application of a number of science concepts, and how things like friction and weight can influence the outcome of an experiment.
