We used a wheel and axle (toy car) in the balloon. When we released the ball we also released kinetic energy. The ball then hit the cup which was attached to the balloon. Potential energy was stored inside the balloon which was released as kinetic energy because it popped.
The hardest part was figuring out what would make the balloon pop. We originally thought that if the ball hit a marble the marble would hit he balloon, but that failed many times
The best part that worked well would be the ball hitting the cup because it worked every time. The best part was the balloon popping.
We divided the tasks by what the person wanted to do. For example Jada put confetti (pieces of paper) in the balloon while I taped the ball to the chair. The way we developed the stages is we agreed on what we wanted to accomplish which was to pop a balloon then we worked from the bottom up. We worked together well and finished what we needed to do.