Question

Why a loud sound is produced when we brust the balloon?

Answer 1

Dear student,

A sound generally occurs when air under pressure inside a balloon is released through a small orifice. This can be felt when we release the mouth while blowing the balloon or untying the thread which tied the blown balloon.

But the explosive burst which occurs when a fully inflated and stretched balloon is pierced by a pin is due to a different reason. It is due the faster expansion of the breaking hole or faster relaxing of the stretched parts of the balloon at the place where pin prick is made. That is, it is the elastic or latex travelling back to position from its stretched unstable position due to the tensile limit,faster than the speed of sound of the air(waves) going out, at the pin hole. This is akin to the boom or explosive sound created by Supersonic planes.

A balloon made of thin rubber is prone to the influence of weather, atmospheric chemicals and also the pressure variations inside when tossing and moving the balloon. So when the pressure mounts at the most vulnerable point in the ski the weakest part may give away breaking due to the tensile properties.( Any material tends to be at its most comfortable state of equilibrium. Hence even if the balloon is not fully inflated, it has tendency o come back to its inert equilibrium at the earliest opportunity.)
I hope you understand