නව විදු ලොව

4. Balloon rocket

·    Take a balloon, some cotton thread, a straw, sticky tape.

·    Stretch the cotton thread across the class and keep fixed only    
      one end.

·    Blow the balloons and pinch the neck of the balloons closed.

·    Tape the each balloon to a straw starting at one end of the 
      thread tracks.

·    release the mouth of the balloon and take the observation.