Why does an inflated balloon shoot off when its air is released?   

Expert Answers
mlsiasebs eNotes educator| Certified Educator
When a balloon is inflated we increase the pressure inside the balloon so that the pressure inside the balloon is greater than the pressure outside the balloon (I.e. the air pressure). When we open the balloon, the air is released so the air inside the balloon is at the same pressure as the air outside the balloon. When this happens, the air escaping from the balloon results in a force in the opposite direction sending the actual balloon in the opposite direction. The escaping air in one direction provides the force in the opposite direction for the balloon to go in the opposite direction.
pranitingale | Student

Air particler have large spaces between them, they also have the maximum kinetic energy and lesser force of attraction between the particles. Therefore, when the balloon is inflated the particles of air in it moves very faster and strikes the walls of balloon from inside which exerts pressure on the inner wall of balloon. When the mouth of the balloon is opened the particles in their direction of movement flows out of the balloon, due to opposite force exerted by the particles the balloon moves upward and keep changing its direction.