Following our exploration into Fedor, the world record breaking hot air balloonist who circumnavigated his way around the world in 11 days, the children were intrigued with how hot air balloons fly.
Over the last couple weeks, during science workshops the Preps have learnt about the science behind hot air ballooning. Hot air balloons work because hot air rises. By heating the air inside the balloon using the flame, it becomes lighter than the cooler air on the outside. This causes the balloon to float upwards. If the air cools down, the balloon begins to slowly come down.
Week 3: Building the hot air balloons
Deer, Cat and Tiger groups each participated in a workshop where they followed a procedural text together to build a hot air balloon using house house materials.
Week 4: Flying the hot air balloons
Unfortunately, none of the three hot air balloons took flight. Each failed for a difference reason and we learnt something with each failed attempt.
Cat – The bag puffed up as it filled with hot air, however the candle placement was too close to the bag and it burnt a little hole, causing cold air to fill the bag. 2 out of the 4 more candles blew out and it sank.
Deer – Following the last experiment, Maddy researched other successful hot air balloons and found a different strategy that involved making a frame with straws to sit around the base of the bag. This ensured that cold air didn’t get in, but unfortunately it got to hot and started to shrink! Maddy blew out the candles and ended the experiment there.
Tiger – The candles were too close to the bag, the design of the structure was flawed. When the children were asked how to improve the structure, they offered thoughtful suggestions e.g. – put the candles closer to the middle of the square of foil so they wouldn’t be near the edge of the balloon.
Each group viewed the Youtube clip below, hoping to find a better way to conduct the experiment.
Week 5:
On Thursday, another hot air balloon was built, closely following the George’s instructions this time. The balloon filled with hot air, but did not fly. We will try again!
