Why an inflated balloon shoots off when its air is released?

Answer 1

To understand why balloons produce a bang, we must fist understand why they burst.

As balloons reach their maximum expansion, they get to a point where the latex cannot stretch anymore and gets stiff and resists any further stretching. This increase in stiffness will cause an increase in the air pressure inside the balloon just before bursting.

While the air pressure inside the balloon does not contain much potential energy, the latex does store terrific potential energy. The rapid release of the stored energy during the burst produces the resounding bang. 

More detailed explanation

When a balloon bursts, the latex splits into various pieces as cracks are developed. The speed of sound in the latex is much higher than the speed of sound in air. The speed of the crack propagation through the latex approaches the speed of sound in the latex. Therefore, the velocity of the crack-faces breaks the sound barrier in air and produces a sonic boom. The latex then violently contracts. The ends of the latex contract so rapidly that they break the sound barrier.

Just like the end of a bull-whip, they create a shock wave.

More the latex breaking the sound barrier, the bigger the bang. The faster the latex is going, the bigger the bang.

(check the related link for a video)

Answer 2

It is a result of Newton's 3rd law of motion - for every action, there is an equal and opposite reaction along the same line. The air rushes out of the balloon, and the balloon goes in the opposite direction and it pushes against the released air.

In more detail, the air inside the balloon is at a higher pressure than atmospheric pressure so the gas molecules inside the balloon are closer together on average than gas molecules outside the balloon. This means that the repulsive forces between the gas molecules inside the balloon are greater than the repulsive forces between the gas molecules outside it. When the balloon is opened, the gas molecules in the open end at the border between the higher pressure interior and lower pressure exterior will experience a greater repulsive force from the gas molecules inside the balloon than the molecules on the outside. This means that they experience a net force pushing them out of the balloon. As these gas molecules are pushed out by the gas inside the balloon, they push back on it with an equal and opposite force (due to Newton's 3rd Law of Motion). This equal and opposite reaction force causes the gas in the balloon to be pushed in the opposite direction to the escaping gas, which in turn pushes the balloon. As more and more gas escapes, the reaction force on the balloon continues to accelerate it, making it shoot off, until enough gas has escaped for the pressure inside the balloon to have dropped to the same level as the pressure outside the balloon.

Answer 3

the air escaping one way will push the balloon the other way

Answer 4

because there isn't enough space for the air inside the balloon, so the balloon stretched so much until it cant any more and it pops

Answer 5

sonic boom