The reason why we did the balloon rocket is because we as a class wanted to find out if blow up the balloon and hold it up, will it change at all but it somehow went a little bit faster.
We did a see,think,wonder and wrote what are the forces for an example:why did it go faster/the balloon,when you lift the chair up.
I think it went faster when you lift the chair up because it changed the angle,and the wind resistance made it go faster.
The forces are:
Drag and thrust.