Air Power! Science with a rocket balloon!
-long piece of threadThread the string through the straw. Then tie the string between two chairs (we used the window valance and then secured the bottom to the couch with tape so that the “rocket” could shoot “up!”) Blow the balloon up and peg the end with the clothes pin to keep the air from coming out. Tape the straw to the balloon. From The Usborne Book of Science Activities Volume Two
-peg (clothes pin)
The tapped air will rush out and propel the balloon forward. The balloon will flatten as it moves along and the air is displaced.