Hot Air Ballons

Today we used a plastic garbage bag, a gas cooker, a cardboard box and a hot air to make a hot air balloon. Before we started Euan fetched a bucket of water just in case anything caught fire. It was very windy outside so we had to make the ballon inside.

We opened the top and bottom of a cardboard breakfast cereal box and made it into a tube. This went over the gas burner to act as a chimney. We lit the cooker and kept the flame very small, then put the chimney over the flame, making sure it was not too near the flame.  The gas heated the air and sent it up the chimney, then sucked in cool air from the holes in the cooker.

With one person on either side of the cooker, we held the bag over the cooker and watched as it filled with hot air. When it started to tug, we let it go and it shot up to the ceiling.

We did not put weights on the bottom of the bag so it tipped over quite easily and let all of the hot air escape.  Then the bag floated gentle down to the floor.

 After a while, the bag got too hot and the plastic started to melt. Next time we will try making the bottom a little heavier, and maybe make the opening a little smaller.

All the pictures are on https://picasaweb.google.com/ReeceSwart/20110130_Hot_Air_Balloons_Part_1#.