How to turn a balloon into a rocket

Making a simple balloon rocket

Safe­ty pre­cau­tions

None.

Equip­ment

  • bal­loon;
  • pa­per straw;
  • rope;
  • ad­he­sive tape;
  • small binder clip.

Step-by-step in­struc­tions

In­flate the bal­loon and hold the neck closed with the clip. Tape a pa­per straw to the bal­loon and thread the string through it. Tie the rope to two beams, re­move the clip… and the “rock­et” takes off!

Process de­scrip­tion

The air pres­sure in the in­flat­ed bal­loon is high­er than that of the at­mos­phere, but the bal­loon re­mains at rest as long as the air pres­sure is dis­trib­uted equal­ly through­out it. When an “exit” ap­pears, the air pres­sure sharply de­creas­es on that side of the bal­loon, but con­tin­ues pro­vid­ing pres­sure on the in­ner wall on the op­po­site side. This pres­sure dif­fer­ence sets the bal­lооn in mo­tion, even as a jet of air steadi­ly emerges from its “noz­zle.”

Try it