Question

We had an experiment that is entitled "balloon rocket" it is an experiment using the force of balloon to make the straw move. it is about law of interaction.

Did the escaping air have to hit anything to make the balloon move??

my answer here is no, because even in space, space rockets can travel even in a vacuum.

is it correct??

Answer 1

Air from a balloon does not need to touch anything in order for the balloon to move. The outside forces around the balloon push down it so it contracts and air is expelled. This propulsion is what moves the balloon.