The first thing I did when making making the rocket was taping three straws to the sides. This helps keep the rocket stable before launch. Then we got a cork that fitted the bottle. The next thing I did was pour vinegar into the bottle until half way full. After we put some baking soda into a square of toilet paper and rolled it. Finally we went outside and launched the rockets. We did this by combining the rocket with the roll of toilet paper then we put the cork on.
Because of miscommunication in my group, our rocket didn't launch. We put in the baking soda into the bottle but didn't put the cork on right so the pressure didn't build up enough to explode.