Hot Air Balloon (The Second Attempt)

After our last attempt to build a working Hot Air Balloon using the Egg Lander, Mr. Chung thought it was necessary that we try again. Unfortunately, this time was no different from the last time. Even though we got the opportunity to bring in our own materials to make the Hot Air Balloon, none of them worked. Why is that?

Instead of being placed in the same group as our Egg Lander, we each got placed in a different group with different people. To start out with, we discussed the best way to build the Hot Air Balloon. In order for a Hot Air Balloon to work, it is necessary that the structure at the bottom should be light, and the amount of candles and the size of the bag should be proportional. If there are not enough candles, there won’t be enough fuel for the bag to fill up with oxygen and allow the structure to rise. Our group decided, with the suggestion of Mr. Chung, to use kabob sticks since they were firm and strong, as well as light and easy to use. We also decided to use a very thin paint drop sheet as the bag since it is light and comes in a big size which can be cut to preferred dimensions. In addition, we decided to use the candles Mr. Chung provided with us last time since they were very light in weight and did not burn out very quickly.

Our group came up with the idea to make the Hot Air Balloon as small as possible, since the smaller the lighter. Because the structure was small, we decided to use as limited number of candles as possible, and therefore should mean that the bag should be small too. We decided to make the structure to have two layers so that the oxygen would not only accumulate on the bottom, but on the top as well, so that the oxygen would rise and cause the bag to expand quicker before the flame dies out or the candle melts. The problematic situation we had was how to light the top candle without making a hole in the bag. In addition, because kabob sticks are thin and the circumference of the candle was wider than the thickness of the kabob stick, we decided to use straws. The straws allowed the candles to be put in the middle of the straw with just enough space cut out on the side of the straw to perfectly fit the candle.

Unfortunately, our design did not work. In the moment, we decided to light only one candle because the bag was too small and we were scared that the lighter might cause a hole in the bag. 

If I were to change something, I would definitely change the size of the bag. The size of the bag greatly impacted and restricted the amount of candles we could put in. I would also have changed the bag itself to something cylindrical with a cover on the top. This allows for the oxygen to accumulate in that space without being wasted and released. I would also increase the number of candles, just in case that while the oxygen is being accumulated into the bag, some of them blow out and are not in a position to be lit again.