|Mr. Dehetre prepping the balloon outside.|
|Students prepping the balloon inside.|
Last spring, three 7th grade students constructed a hot air balloon in STEAM. Due to poor weather conditions last spring they didn’t get to fly their balloon but vowed to one day fly. On a very cold day in December, Sophia, Becca, and Eliza met with Mr. Dehetre to finally fly their aircraft. The girls, now 8th graders, were amazed at how high the balloon was able to rise. The outside temperature was about 10°. They estimated that the balloon traveled a good 100 to 150 feet upward.
How does it work? The key is density. The air outside of the balloon and within the balloon have different densities due to the heating of the air with a propane burner. Warming the air inside the balloon causes its atoms to move faster than the atoms of the air outside of the balloon. Having fewer atoms within the balloon at the same air pressure as the air surrounding the balloon makes the balloon less dense causing it to float.