04 Nov 2013
In science 3/4MG have been learning about air pressure. We talked about how air pressure makes ball and bicycle pumps work and some musical instruments rely on air pressure to make a sound. Working in small groups,we designed balloon rockets that could travel up to five metres along a line. The students experimented by changing the line from wool to fishing line and discovered the distance the balloon travelled varied due to friction. By doing these experiments the students could see how the rocket gained its propulsive force as the compressed air rushed out the neck of the balloon. After the experiments the groups compared their results and thought about how a balloon rocket works like a space rocket except that a balloon rocket's energy is stored in the stretched rubber and there is compressed air in the balloon instead of chemical fuel.